Castiel

"I'm the one who gripped you tight and raised you from perdition."

- Castiel's first line, speaking to Dean Winchester.

Castiel, a Fallen Angel of the Lord, was responsible for pulling Dean Winchester out of Hell in "Lazarus Rising," on God's command. It was his job to help prevent Lilith from breaking the 66 Seals that, once broken, would release Lucifer from his cage. Once Castiel learned that the angels wished to free Lucifer, he defied his angelic brethren and died trying to help Dean prevent Sam from breaking the last seal.

After he was killed by Raphael, Castiel was resurrected by God and appointed as the Winchester brothers' protector to prevent them from becoming the vessels of Michael and Lucifer. When the Apocalypse was averted, he was again resurrected with new powers. He then started a civil war in Heaven to prevent Raphael from restarting the Apocalypse. Thinking he couldn't be outsmarted by a demon, Castiel teamed up with Crowley to claim the souls of Purgatory. He ended up betraying Crowley and absorbed all the souls, resulting in his powers reaching the level that of a god, but at a high price: the powers that the evil souls granted him had warped Castiel's mind, causing him to proclaim himself as the new God.

Castiel later agreed to the advice of Dean to release the souls back into Purgatory. While seemingly successful, it turned out that the most powerful entities from Purgatory held on to Castiel, and overpowered him. When the Leviathans leave to take over new forms Castiel was presumed dead, but survived - apparently resurrected by God yet again. Dean later accidentally finds Castiel as an amnesiac healer called Emmanuel. After taking on Sam's madness and experience in Hell in order to save the Winchester and redeem himself for what he did to Sam, Castiel had become insane. However, his sanity is returned to an extent when a signal was sent to all angels upon the discovery of the Word of God and the appointment of a new prophet. He then aides the Winchester brothers against Dick Roman, only to be transported to Purgatory with Dean.

While Dean returns, Castiel is not with him. While his condition is initially unknown, it's revealed that he spent most of his time running from Leviathans and that he didn't escape Purgatory with Dean as he had planned to stay as a form of penance.

As of the episode Blood Brother, it has been revealed that Castiel is a Seraph, when he says it is a risk to jump through the purgatory portal with a Seraph. It is yet unknown specifically when he ranked as one, although it may be possible that when he said he was given improved powers by God, he actually meant he was no longer a regular angel.

Appearance
As an angel, seeing Castiel's true form will result in blindness, as the appearance of his natural visage is so overwhelming that it is capable of burning human or demon eyes from their sockets (as seen in "Lazarus Rising"). However, Castiel stated certain, "special people" are able to tolerate his true appearance and voice. Although his true form has never been seen, it is known that he has two feathered wings and his true form is approximately the size of the Chrysler Building. It is presumed to be very tremendous and terrifying, as the mere image of it was enough to cause Crowley to flee in fear of being smited.

For humans, they see him as the appearance of his vessel, Jimmy Novak, who is an average man in his thirties. He sports a pair of dress shoes, a black suit, an unbuttoned white-stripped dress shirt, and loosened blue necktie accentuated by a beige trench coat. Although he has a very dire demeanor, his outward appearance radiates a natural calm and serenity which makes conversation easy and direct. He occupied Jimmy's body because he had prayed for it. Since his third resurrection, his appearence has changed. He lost his trench coat upon his third death and when he became amnesic, he wore different clothes. Upon regaining his memories, Dean gave him back his trench coat, but he still wore Emmanuel's clothes until he became insane. Now that he's insane he wears his trench coat and hospital scrubs.

Castiel also possessed Jimmy's daughter, Claire Novak, for a brief time when Jimmy was still undecided if he would take back the angel. It would appear that Castiel could possess any willing member from Jimmy Novak's bloodline, not unlike how Michael was able to possess John Winchester, and the two of his three sons.

Personality
Like most angels, Castiel expresses little to no emotion. Despite this, he does not display the blank apathy or mocking superiority complex that seem to characterize angels such as Uriel or Lucifer. His lack of emotion and understanding of human traits such as sarcasm has often led to humorous situations throughout the show and have occasionally almost got him into trouble with humans, ultimately leaving Dean or Sam to amend the situation.

Unlike many of his brethren, Castiel still has faith in his father, though not to the near zealot-like level displayed by Michael. While he admits he may not always understand what God wants and question the reason for it, he would always follow his father to the best of his abilities. This, along with his interest in humans, has caused other angels to label him as odd or naive. Anna and Lucifer have both demonstrated this, with Anna calling him a hypocrite for refusing to rebel in order to gain more freedom. Castiel frequently exhibits what could be referred to as friendly affection towards Dean, and seems to at the very least come close to expressing regret, hesitance, and anger several times.

Being around the Winchesters and his own experiences in the War have taught Castiel several "tricks" that have helped him during the show. While not possessing free will in the same sense as a human, Castiel has learned how to "bend" the rules at times in season 4. The best example is when he informs Dean about Chuck's archangel thereby giving Dean the idea to use him to save Sam from Lilith ("The Monster at The End of This Book", season 4 episode 18). He also is able to distract Meg long enough to use her and a similar trick Uriel performed to free Alistair to free himself from a ring of holy fire ("Abandon All Hope"). It is also possible he learned from the demon Crowley to wipe out loyalists of his adversary e.g. Raphael. Castiel also considers himself to be the Winchester's personal guardian angel.

When Castiel is brought back from the dead after Lucifer kills him, he begins to develop a sense of pride. During Season 6, Castiel's personality begins to change. It is also because of this pride that Castiel makes a deal with Crowley, and starts the civil war in heaven.

Upon absorbing the souls, Castiel claimed himself to be God, though later Death refers to him only as a mutated angel. Previously acting kind and assuring but also fierce at times, Castiel had now become nearly purely cold and absolute in his decisions, as seen when he kills Raphael without any second thoughts. Mere seconds after, he also demanded that Dean, Bobby, and Sam kneel before him and tell him they love him or he will destroy them if they forgot their place and rise up against him.

After recovering his memories, Castiel's normal personality more or less returned, and he was overcome with guilt over what he had done, how many he had killed, and for releasing the Leviathans, even questioning why he was still alive. Following his awakening, his personality was greatly modified, due to a combination of what he had taken from Sam and his own guilt. It made him inattentive, overly calm, uncaring and seemingly dim. He also became a pacifist, and refused to fight, even when being attacked, as well as overly optimistic, perceiving many negative things in a positive way.

However, in "Survival of the Fittest", he stepped in front of Dean when Dick approached him (thus participating in conflict), and held Dick in place as Dean kills him.

After he and Dean were sent to Purgatory, his sanity and orginal personality was resored, although he himself states nobody could ever be sure if he is indeed sane. Following his return, Castiel displayed a slightly more laid-back personality and a less detached persona as well as a taste for human things, as he commented how he missed watching televison.

Early Life
Discussions with Uriel suggest the pair were children by angel standards when Lucifer rebelled against Heaven and refused to bow down to humanity. While his brother was instantly enthralled by Lucifer's power and charisma, Castiel remembered being frightened and disturbed by the rebellious archangel. Castiel had been stationed on Earth for at least 2,000 years while being in the same garrison as Anna Milton, who acted as his superior, and Uriel. Castiel was present when the world was first created. He watched as the first fish emerged from the ocean. He also watched them build the tower of Babel, among other historic and biblical events.

In 2008, Castiel speaks with his true vessel, Jimmy Novak, in Pontiac, Illinois. When Jimmy is watching television, Castiel's voice distorts the picture and causes him to scream in pain and his body to spasm until he finally blacks out. Later, Castiel would tell Jimmy to put his in arm in boiling water and that he would be unharmed as a way to prove his faith. With his wife believing that he was going crazy, Jimmy asks Castiel what he wants from him and how he can help. Castiel explains that he needs to use Jimmy as a vessel, to which Jimmy agrees to as long as his family is protected. After receiving consent, Castiel possesses Jimmy. Before he leaves, Castiel is confronted by Jimmy's daughter, Claire, and tells her that he is not her father.

Season Four
When Dean Winchester broke the first of the 66 Seals that would allow Lucifer to walk free, the angels took action. They fought their way to Hell and Castiel freed Dean from the pit. Dean awoke in a grave and made his way to the surface, not knowing how he had been resurrected; the only clue he had was a large imprint of a hand near his shoulder.

After reuniting with Bobby Singer and Sam Winchester, Dean tried to learn what had rescued him from Hell. He also discovered that he'd been dead and buried for four months. Eventually, Dean took matters into his own hands and with Bobby's help, set a trap for the creature and protected himself and Bobby with multiple Devil's Traps and other anti-demon devices.

Castiel arrived and the hunters shot at him as he passed through the Devil's Traps with ease. Castiel quickly knocked out Bobby with a mere touch and Dean stabbed him with Ruby's knife but it had no effect. Castiel explained who he was to Dean and that God has work for him.

After people who were supposed to be dead seemed to be rising from the grave, Castiel appeared to Dean and explained to him that this was one of the 66 Seals, "The Rising of the Witnesses." Castiel told him that Lilith was attempting to break 66 of the seals which would lead to Lucifer walking free on Earth and then the Apocalypse would begin. The angels had been fighting to stop the demons, but the odds were against them. He explained to Dean that he must help stop the breaking of the seals as well. Castiel also showed that he was not a force to be underestimated or even taken lightly as in a chilling tone, he told Dean to start showing him some respect or he'd change his mind and throw him back into Hell again.

One day when Dean was asleep, he woke up to find Castiel sitting beside him. Castiel, without speaking, tapped Dean and brought him back in time to an important few-day period. It showed Dean the connection between Azazel and Mary Winchester, and answered questions that had always been on his mind. Castiel said that the reason he had brought Dean back to that period was to make sure that he was caught up with all of the facts. He also explained that the angels are still unaware of Azazel's endgame. Castiel also told Dean about Sam's developing abilities and that he was going too far down a dark path and that if Sam did not stop using his powers, then the angels would kill him.

Sometime later, Castiel and his partner Uriel met with the Winchesters when they were in the middle of hunting a witch. The angels explained that the witch was trying to summon the demon Samhain from Hell and that this was another one of the 66 Seals. The angels said that they would have to destroy the entire town and all of its residents to ensure that the seal would not be broken. The brothers argued against this and assured Castiel and Uriel that they could stop the witch from summoning Samhain. While Uriel wanted to smite the town anyway and drag Dean and Sam away, Castiel agreed with them, later discussing with Uriel his disdain for humanity and their true orders. Unfortunately, the Winchesters failed and Samhain rose, breaking another seal. After Sam exorcised Samhain with his powers and stopped him, Castiel met with Dean in a park and revealed that the angels true orders were always to follow Dean's orders, not to smite the town and that this was a test of Dean's battlefield leadership. Castiel reveals that he always hoped that Dean would chose to save the town whether or not they failed and that he secretly harbors doubts about Heaven and its plans.

When the angels learned that a woman named Anna Milton could listen in on angel's conversations they grew worried. If the demons were able to get to her before them, the demons would know everything that the angels were planning. But Castiel knew the truth: Anna had once been an angel, a superior to him who disobeyed. She cut out her Grace and fell to Earth, where she was reborn as a human. Castiel and Uriel knew though that the only way to ensure the safety of their plans were to kill Anna. While Castiel was hesitant about this, Uriel enforced the idea that it was absolutely necessary. Castiel and Uriel found Anna along with the Winchesters. The angels ordered Sam and Dean to hand over Anna, but they refused. The angels attacked them and almost retrieved Anna, but were sent away by a ritual Anna performed. They later were able to find Anna with the Winchesters again, but soon discovered that they had been led into a trap when Alastair arrived with a group of demons. The angels and demons fought over who would take Anna with Castiel fighting Alastair. Castiel proved no match for the demon, with his powers being useless, but Dean saved him despite being on opposite sides of the Anna situation. In the end, Anna retrieved her Grace and became an angel again and Alastair's body was destroyed, defeating him. Grateful for Dean saving him, Castiel held Uriel back from attacking Dean in revenge and they left to chase after Anna.

When Alastair tried to break another seal by killing two Reapers on the night of the Solstice, Castiel managed to capture him having pretended to be Bobby to send the Winchesters after the seal. The angels held Alastair captive and when seven angels had mysteriously been killed, Castiel assumed that demons were behind the attacks. He and Uriel recruited Dean to interrogate the demon. During the interrogation, Anna returned and spoke with Castiel. She told him that she knew how he was feeling and that he was beginning to develop human emotions. Castiel refused to believe this and yelled at her, causing her to leave. Shortly after, the Devil's Trap Castiel had made to hold Alastair somehow malfunctioned and Alastair nearly killed Dean. Castiel fought the demon but was almost defeated when Sam came to his rescue, using his psychic powers to kill Alastair to Castiel's shock after torturing out of him that the demons weren't responsible for the angel deaths. While visiting Dean at the hospital, Sam criticized Castiel for being so cold-hearted as to risking Dean's life. This sunk into Castiel's head and he went to Anna for help, telling her he needed to know what to do; she told him it was time for him to decide on his own for once. Castiel investigated the broken Devil's Trap further and learned that it was Uriel who was behind the malfunctioning Devil's Trap and the angel killings. Uriel reminded Castiel of the times when Lucifer was one of the greatest angels and also spoke about how God isn't doing anything and they must follow someone who would. Castiel refused and the two angels fought. Castiel was no match for Uriel and was beaten down but was saved when Anna appeared and killed Uriel with his own Angel Blade. Castiel then went to Dean and confirmed that Dean was responsible for breaking the first seal by giving in to Alastair's torture. Dean begged Castiel to find someone else because he wasn't fit to stop the Apocalypse.

Castiel later appeared when Dean interrogated Chuck Shurley, who was writing a book series based on the Winchester brothers, explaining that Chuck was a Prophet of the Lord. When Dean asked him for help in saving Sam from Lilith, Castiel was initially hesitant to help, but dropped him a hint by telling him that Prophets are protected by archangels, and that if a Prophet is in the same room with a demon, then the archangel will descend to smite the demon.

Castiel then came to Dean while he was dreaming and told him to meet him at a certain location, saying that he had something to tell them. But when Dean and Sam arrived, they found him unconscious in a wrecked building with dead demons. When he awoke, the brothers found that Castiel had abandoned his vessel, Jimmy Novak, who describes being possessed by Castiel like "being chained to a comet." When Dean, Sam, Jimmy and Jimmy's daughter, Claire, were being held hostage by demons, Jimmy was shot and Castiel returned to possess Claire and helped save them all. While Castiel tried to comfort a dying Jimmy, Jimmy pleaded with Castiel to take him back as a host and Castiel accepted. When Dean asked Castiel what happened, he coldly replied, "I learned my lesson while I was away, Dean. I serve Heaven; I don't serve Man. And I certainly don't serve you."

Later in "When the Levee Breaks" Castiel was summoned by Dean, who was screaming for three hours for help. When Castiel arrived, Dean asked him what happened in Heaven, but Castiel wouldn't say. Then Castiel recruited Dean in the service of God and his Angels. Castiel told him to wait till the Angels summons him. A few hours later he freed Sam from Bobby's panic room in which he was held captive, because of his addiction. Later Anna confronted Castiel about why he released Sam. Anna said that Sam was even worse than they had expected. Castiel told he has his orders to follow and then said to Anna that she shouldn't have come. The next moment two Angels stood beside her, and took her captive.

Later Zachariah brought Dean to a chamber, so he would be safe for the release of Lucifer. Zachariah told him that the final seal would be broken that night. Although had a fight with Sam, Dean tried to contact him on his cellphone, leaving a message on his voicemail. Later Dean wanted to talk with Sam and summoned Castiel by breaking a Stone Angel on one of the tables. Dean asked to visited Sam, but Castiel said he could go everywhere except to Sam. Dean asked what they were going to do with Sam. Castiel said that Sam is going to do it to himself, but he didn't want to say more. He said it was his destiny. Dean said that destiny was just a bunch of lies, to keep him in line. Dean tried to persuade Castiel to help him, but Castiel said that they would be all be hunted, that they would all be killed. In response, Dean said to him that this is worth dying for. But to Dean's disappointment, Castiel refused.

A few moments later, Castiel confronted Dean and drew an Enochian Sigil on the wall with his own blood. Then Zachariah appeared and asked what he was doing. Castiel pressed his bloody hand on the sigil, banishing Zachariah. He then said that Lillith is the final seal and that Sam is going to break it. He said he knew someone that knew where Sam was and teleported Dean with him.

Castiel teleported Dean and himself to Chuck, the prophet of the Lord. Chuck was confused and said that this is not supposed to be, that they were not in the story. Castiel said that they would make it up. When they found out that Sam was at Saint Mary's, Chuck’s computer goes off and bright light fills the room. Castiel said it is the Archangel and teleported Dean to Saint Mary's, so that he could hold the Angel off. At Chuck’s, Castiel looks up at the bright light. Chuck puts his hand on Cas’s shoulder, and when Castiel gives him a look, he removes it.

Season Five
After witnessing the release of Lucifer from Hell, Dean and Sam go to Chuck's house to find Castiel. There they are told by Chuck that the archangel smoked Castiel - literally - and they even find one of his teeth tangled in Chuck's hair. Later, when the Winchesters are trying to track down Michael's sword in their father's old storage unit, Zachariah and his angels arrive to inform Dean that he is Micheal's sword—in other words, Micheal's vessel. When Dean refused to give his consent for Michael to possess his body, Zachariah started inflicting various kinds of physical pain on him and Sam (breaking Sam's legs and removing his lungs, and giving Dean stage-four stomach cancer), all the while refusing to kill them. Castiel then miraculously appeared and dispatched Zachariah's men, then forced Zachariah to heal the Winchesters and leave. He then used his powers to carve Enochian Sigils on their ribs, keeping them hidden from all demons and angels, including Lucifer.

After rebelling against the angels, Castiel's powers began to deteriorate whilst he searched for God using Dean's amulet. However, despite his vanishing strength, he continued to be invaluable to the brothers saving them on numerous occasions.

In "Dark Side of the Moon", when the brothers are ambushed and killed by several hunters furious with them for causing the Apocalypse, Castiel warns the brothers that Zachariah is looking for them in Heaven and they should attempt to contact an angel named Joshua, who is rumored to speak to God. When the brothers return from death, Sam reveals that God wants nothing to do with them, causing Castiel to abandon his belief in God and return Dean's amulet, stating that it's worthless.

In "Two Minutes to Midnight," (at which point Castiel had been stripped of all his powers) he assisted Sam and Dean against the 3rd Horseman, Pestilence, by cutting off his finger and obtaining one of the 4 rings needed to seal Lucifer back into the pit. In the Season Finale when Michael (in the vessel of Adam Milligan) was about to fight Lucifer (in the vessel of Sam) Dean intervened saying he wished to speak with Sam. This prompted Michael to remove Dean, however, before he could respond Castiel threw a molotov of holy fire at Michael sending him back to heaven for a brief time. Lucifer turned to Castiel, furious by the fact that Castiel harmed his brother, and caused Castiel's vessel to explode. Shortly after the battle between Sam and Lucifer, Castiel was resurrected by God with his angelic powers restored and upgraded, allowing him to restore Bobby Singer to life. Castiel, presumably now a seraphim, said that he needed to return to Heaven to restore order to the anarchy that will follow Michael's departure.

Season Six
After the Apocalypse was averted, Castiel returned to Heaven where other angels awaited him. He tried to tell them about freedom, but none of them understood. Castiel finds out that Raphael wanted to take over and follow Michael's departure and restart the Apocalypse. Unable to stop him, Castiel wants to turn to Dean, but can't. Then Crowley shows up with a deal to find Purgatory and offers Castiel power to stop Raphael. So Castiel begins a civil war in Heaven.

When Sam and Dean found out the plagues were unleashed upon the Earth, they called Castiel for help. Castiel showed up and told them the Angelic Weapons were stolen from Heaven. He also claimed that he didn't know what or whom brought Sam back from Hell.

During their investigation, they find out that an Angel has been moonlighting as a crossroads demon. To locate the angel's name, Castiel performed a ritual to find the angel that bought the soul. When Castiel learned it was his old friend, Balthazar, an angel follower of Raphael showed up and attacked Castiel. Castiel managed to defend himself and let the angel get away, but the angel knew that Balthazar was selling pieces of the Staff of Moses. So Castiel, Dean and Sam try to find Balthazar first, and when they do, Balthazar admitted that he stole the weapons from Heaven and that he want to live in freedom. When Balthazar disappears, Castiel is confronted by angels who want to kill him. Castiel asked them to join him, but they refused and Castiel killed them. Afterwards, Raphael showed up and told him that they were his followers and smashed Castiel. Just as Raphael was about to kill Castiel, Balthazar showed up and used the weapons from Heaven to destroy Raphael's vessel. Eventually, Sam and Dean showed up and were able to trap Balthazar in a circle of holy oil, but Castiel lets Balthazar go after they force him to let go of his hold on the soul with Castiel's reason being that he owed Balthazar his life.

Dean becomes more and more disturbed by Sam's behavior, and prays for Castiel's help. Castiel doesn't respond until Dean calls him about a possible loose nuke, much to Dean's aggravation. Castiel apologizes, but reassures Dean on his theory that Sam is not Lucifer, explaining that all angels would feel his presence if Lucifer was free. Castiel also states he doesn't know what's wrong with Sam, but he promises to make inquiries.

Dean calls on Castiel once he has Sam unconscious, and asks for him to diagnose Sam. Castiel informs both brothers that physically, Sam is perfectly healthy, but his soul is missing. He guesses that Sam's soul is still in the cage with Michael and Lucifer. When Sam goes with Samuel as his only lead, Castiel follows Sam and Dean to the Campbell Compound to check if Samuel has a soul or not, which he does. However, before he can do any more to help, he states he needs to return to Heaven, but reassures Sam and Dean that their problems "always come first", and will keep in touch.

Castiel is later called on for assistance by Sam, who tricks him into leaving Heaven by saying he and Dean have found the Ark of the Covenant. Sam tries to coerce Castiel into joining them along with the demon Meg and her minions to confront Crowley, but fails as Castiel knows Sam can't harm him. However, recignizing that Sam really does need help, Castiel decides to help anyway. Castiel tries to track down Crowley by means of a ritual, which leads them nowhere. When the group is caught by Samuel as they search through his quarters, Dean asks for the angel to leave back to their motel.

Sometime later, while Sam and Dean are looking through records trying to find Crowley, Castiel is confounded by watching porn, which he states just happened to be on the TV. He creates an awkward moment, even weirding Samuel out upon arriving at their motel. He leaves with the group after Samuel gives them the location of Crowley's prison. Before leaving for the prison, Castiel suggests to Dean that he doesn't think restoring Sam's soul is wise. He supports his statement with the fact that his soul has been locked in the cage with Michael and Lucifer for more than a year, and they have been doing nothing other than taking their frustrations out on Sam. He theorizes that if they try to force the damaged, tortured soul back into Sam, and if they fail to deal with the problems, then Sam will suffer horrifically.

The group then leaves for the prison, and Castiel finds a back entrance inside. Shortly after, hell-hounds come after the party. Meg distracts Castiel by kissing him, and steals his angelic blade. Castiel, surprisingly, responds to this by kissing her back, stating he learned that from the porn he was watching earlier. The boys then run off while Meg holds off the hell-hounds with the angel blade. Later, Castiel is banished by a blood sigil cast by Samuel, while the Winchesters are taken captive.

While Crowley has the boys pinned to the wall, Castiel reappears, carrying a large bag. After Crowley taunts him about his losing war against Raphael, Castiel reveals that the bag contains his salvaged bones. The angel asks the King of Hell one last time if he can restore Sam's soul or not. Crowley says he cannot, and Castiel proceeds to burn his bones, turning him to ash.

A short moment later, outside the prison, Castiel later admits that he is on the losing side of the civil war in Heaven, and expresses disappointment as he wishes much of the time that circumstances were different as he prefers being on Earth with Sam and Dean. Dean then reassures the angel that they will help in whatever way they can, and that the brothers are his friends. Castiel then turns to Sam, and reassures him that they will find another way to get his soul back. Sam then asks him to dispose of the monsters that still remain inside the prison, to which Castiel presumably leaves to do so.

After Sam gets his soul back, Castiel comes to check up on him, and tells Dean that he doesn't think Sam is ever going to wake up. A few hours later Sam wakes up and reunites with his brother. Later on Sam, now with his soul, calls Cas. Castiel comes and tells Sam he is glad to see him well, despite everything. Sam catches on and tricks Castiel into telling him the truth.

In "My Heart Will Go On," Castiel saves Sam and Dean from Fate, when she tries to get her revenge for



stopping the apocalypse. He tells the brothers if they want to live, they need to kill Fate. So Sam and Dean draw Fate out and just as they face their death, time freezes. Castiel confronts Fate and she reveals the real reason why Balthazar saved the Titanic. It was because Castiel ordered Balthazar to do it for the souls. She threatens to kill Sam and Dean unless Castiel fixes history. Castiel orders the creeping Balthazar to stop and right history.

In "Frontierland," Cas returns to send Sam and Dean back to the Wild West so the brothers could acquire ashes of the phoenix, the one thing that could kill the mother of all. He tells Sam and Dean they have only 24 hours, after that he will no longer be able to find them. During the time the boys are in the Wild West, Castiel's lieutenant, Rachel, confronts him about his side dealings Castiel is doing to win the war. This leads to a duel between the two, and Castiel emerges the winner and wounded. He soon heads to Bobby's, draws a symbol in his blood and passes out. As time grows short, Castiel re-awakens, but is very weak and low on power. In order to "power up" he tells Bobby he needs to touch Bobby's soul. Once powered up, Castiel brings the boys back.

Now with the ashes, the hunt for Eve is on. Castiel comes to Sam and Dean asking for Eve's location, but they too are unsuccessful. Sam suggests that they find a monster who would be willing to give them Eve's location. Castiel finds and brings Lenore, who gives them Eve's location, in exchange for her death. Sam is hesitant, but Castiel brings Lenore her end. This action makes Sam and Dean concerned about Castiel and his circumstances. Once they arrive in Organ, Castiel discovers he can't use his powers, and is now powerless, thanks to Eve. Castiel is later revealed to be working with Crowley after the Winchesters' encounter with Eve.

The truth finally comes out in "The Man Who Would Be King." Castiel recounts history from his point of view and how the Winchesters inspired him. Castiel also begins to notice that Sam, Dean and Bobby are getting suspicious of Castiel and believe he is working with Crowley. Castiel recounts about his return to heaven and his favorite place (the heaven of a 40 year old man who drowned in a bath tub). This is after him bringing back Sam from hell, sans his soul.



At the time, Castiel did not know Sam didn't have his soul. He also tries to get other angels to embrace freedom, but the angels don't know how. Then Raphael tries to make Castiel bow to him, and Castiel refuses. Due to his misfortune, Castiel is no match for him. Castiel tries to get help from Dean, but seeing Dean retired makes Castiel rethink this. Then Crowley approaches Castiel with a deal, so Cas can become more powerful. Castiel begins his deal with Crowley. With this deal, Castiel starts the civil war in heaven. But when Crowley begins to threaten the Winchester's lives, Castiel becomes protective of them. Although Castiel managed to keep the secret for a while, he slipped up with information he got from spying on them. Later the boys trapped him in a ring of holy fire and confront him about his betrayal. When demons come, Castiel tells the boys to run and they leave him in the ring of holy fire. Crowley comes in and saves him. Castiel leaves, and comes to Dean, trying to explain the situation. Castiel tells Dean that he did this for Dean but Dean does not want it this way. Castiel responds that Dean can't stop him and says he's sorry and disappears.



In "Let It Bleed," Castiel has taken one of the Campbell diaries, and is investigating an incident in which H.P. Lovecraft opened a portal to another world. Sam prays for him, telling Cas that Lisa and Ben have been kidnapped by Crowley, and asks for help. Castiel listens unseen, and does not answer, but goes to confront Crowley. He insists that the demon not harm Lisa and Ben, but Crowley refuses to make such a promise. Balthazar later calls him. He asks Cas if he is planning on opening the door to Purgatory; Cas lies that he is not, but Balthazar is not fooled. Castiel asks if he is with him, or not. Balthazar says he is.Castiel goes to Dean, arriving just in time to save him from a demon. He apologizes for Lisa and Ben, revealing that he did not know Crowley's plan. Dean is skeptical, and angry. Castiel asks him again to support his decision to tap the souls in Purgatory. He pleads with him that he has always done what the brothers needed him to, asking little in return. Cas asks them to trust in him, and promises to bring him his family afterward. Dean is unwilling, and Castiel leaves. After Dean and Sam rescue Lisa, Castiel comes to the hospital where the gravely injured Lisa is not expected to survive. He apologizes again, but Dean is not forgiving. Castiel says that he did not come for Dean, then places a hand on Lisa's forehead, healing her. Both Dean and Cas acknowledge that this does not change their situation, but Dean asks for an additional favor. Castiel removes all Lisa and Ben's memories of Dean. Later Castiel finds and takes Dr. Visyak, the creature he needs to open Purgatory.

In "The Man Who Knew Too Much," Castiel and Crowley torture Dr. Visyak until they obtain what they need to open Purgatory. She escapes and contacts Bobby and the Winchesters, telling her story before dying in an alley from her injuries. Castiel comes to the three hunters, who are outraged. Dean tries to argue with him again, but Cas cuts him off, saying he no longer cares about Dean's opinion. He then touches Sam's head, breaking the mental wall, and promising to repair him as long as Dean stops the opposition.

Castiel meets with Crowley, who has assembled the necessary ingredients. The angel wants to renegotiate their deal. He will not give Crowley the souls, so Crowley can either flee or die. The demon leaves Castiel with the blood for the ritual. Later, Castiel confronts Balthazar. He says that Dean is coming, and someone among them is a traitor. Balthazar asks him who it is, and Castiel lies that he does not know, and wants Balthazar to investigate. While the other angel is distracted, Castiel stabs and kills him. Just before the ritual is meant to begin, a cloud of demons descends around the building, and Crowley appears. Castiel tries to kill him, but cannot. He has a new partner in Raphael. Castiel is surprised at the partnership with their differing goals, but both seem to think they have taken the best course available. They demand the blood; Castiel throws them a jar and leaves. Crowley conducts the ritual, and though Bobby and Dean try to interrupt, completes it.

Nothing happens and Castiel reappears. Crowley realizes that he switched the blood, and conducted his own ritual. Castiel displays his power briefly in a flash of energy. Crowley, realizing the game is up for the time being, wisely disappears, and Raphael asks for mercy.

But Castiel is not in a forgiving mood. He snaps his fingers, obliterating Raphael to pieces in mere seconds. He turns to Dean and Bobby. He was right, he says, and he did save them. Dean nervously agrees, then suggests that Castiel should return the souls, and disarm himself. Castiel says he has Raphael's followers to deal with. Dean is worried, and reminds Castiel that he is family, and he doesn't want to lose him. Castiel says that he has no family anymore; he will not give up the souls.

Using that moment, Sam stabs him from behind with an angel sword, but nothing happens. Castiel greets him, then says the sword will not work because he is not an angel anymore. He says that he is their new God, and that they must venerate him, or be destroyed. As he says those words, Dean, Sam and Bobby look on in horror, realizing with shock that their former ally and friend has become a power-hungry angel who believes that he is God.

Season Seven
Castiel waits for Sam, Dean, and Bobby to show their respects. Bobby goes to his knees, and motions for Sam and Dean to do the same. Dean begins to kneel, but Castiel stops him, and orders Bobby to stand, saying that there is no point if they do not mean what they do. Castiel observes, without turning to look, that Sam is not doing well. Dean reminds Cas that the former angel promised to fix Sam when it was over. Castiel cuts him off; his promise was contingent on Dean not opposing him further, and oppose him Dean did. Castiel tells them he has no need to kill them, though he no longer has any regard for them, and will let them live if they do not plot against him.

Castiel sets out to right the wrongs he sees. He destroys Raphael's followers in Heaven, and tells the angels that he no longer thinks free will is what Heaven needs. Instead, he will give them a firm hand. He appears in a church, reveals his identity, and smites a hypocritical preacher. He leaves an image of himself in the stained glass as he departs, and accidentally burns a pew as welts appear on his hand.

He finds Crowley hiding in a RV, and tells him that he may retain his position as King of Hell, but that Castiel will choose which souls he receives. He leaves after looking at yet more open places on his skin. He gives money to a blind man on the street, and heals the man for his faith. The man is grateful, but surprised when his first sight is of Castiel's blistering face.

&amp;nbsp As he walks through the street, he sees a blind beggar asking for money and declares him to be a true disciple of God, and heals his eyes as a miracle. At a nearby bathroom, he looks in the mirror and stares at the blisters covering his face and hands. His stomach begins to bulge and contort as the Leviathans demand to be let out. He puts them down and says, "I control you."

Sam, Dean, and Bobby summon Crowley, who reluctantly gives them a spell to bind Death. They work it, and an irritated Death appears, followed shortly by Castiel. Dean orders Death to kill 'god'. Death says he sees only a mutated angel, one whose vessel is disintegrating. Castiel, sounding uncertain, says he will heal himself when his works are complete. Death replies that Castiel swallowed Leviathans when he emptied Purgatory, not just souls, and that is the danger. Castiel frees Death from Dean's binding spell.

Castiel leaves. At a political election office campaigning for a senator of whom Castiel disapproves, he is stopped by one of her aides. Castiel asks the man to see that he is a good god, that he means the best for his children. He awakes some time later in a pool of blood on the floor. He has slaughtered the entire office. At Bobby's place, Sam prays for Castiel to reconsider and give up the souls. A few minutes later Castiel appears, disheveled, bloody, and looking ill. He says he needs their help.

He listens to Sam's call and agrees to put all the souls back in Purgatory. Before the opening of the door, he expresses regret at what he has done and wishes that he could have restored Sam back to normal, and promised to do so if he survived. After he lets out all the souls, Cas passes out but wakes up. He automatically begins to contort and struggle as the Leviathan had held on to his body are trying to take over.

Castiel is soon overpowered by the Leviathan who in turn take control of him, presumably taking him far away. They begin by throwing Dean and Bobby against a wall before saying that they're going to have fun now.

Soon after flinging them, his vessel begins to ooze black blood, and Dean smugly points out that the vessel can't contain the power of the Leviathans. They leave saying they will be back for Dean.

The Leviathans are able to guide Castiels vessel to a water reserve and the vessel explodes in a whirlpool leaving the Leviathans to escape into the water. Later Cass' trenchcoat is found, Dean folds it up and takes it with him.

It was later revealed in "Slash Fiction" that the Leviathans learned of Sam and Dean's aliases from Castiel's mind before they sent him away.



Castiel returns in The Born-Again Identity, having been resurrected by God yet again, but has forgotten his previous life as an angel. He now lives as Emanuel, a healer with his wife. Dean finds him again after word of his healings get out. Dean saves his wife and asks him to heal Sam. After regaining his memories as he is defeating multiple demons, Castiel attempts to rebuild the wall in Sam's mind only to discover that it was destroyed. In one last effort to redeem himself Castiel shifted the hallucinations of Lucifer from Sam's mind to his own in order to save Sam. Castiel then looked on in horror as he could only see Lucifer's face as he is committed to the Mental Institute.

In "Reading is Fundamental", Castiel has recovered from his insanity, albeit with a more carefree, eccentric personality. He reveals that he is no longer affiliated with Heaven, thus he is a Fallen Angel.



In Survival of the Fittest he returns to the Winchesters and encounters Crowley, who is holding a grudge for Castiel betraying him. Crowley reveals that Castiel is essential to defeating the Leviathans, being able to see past their human exterior. He at first refuses to help, but after some convincing he agrees to help. Dean and Castiel confront Dick, and succeed in killing him, however the two are transported to Purgatory (Castiel at this time appears to regain his personality.) Castiel then disappears leaving Dean to fend for himself, alone in Purgatory.

Season Eight
In We Need To Talk About Kevin, Dean escapes Purgatory with the help of the vampire Benny, but Castiel is not with him. Dean later tells Sam that Castiel died in Purgatory, that it got hairy near the end and Castiel "let go." While Dean doesn't elaborate, this clearly affects him greatly.

Dean has flashbacks of Castiel and it was revealed in What's Up, Tiger Mommy? that he had succeded in his relentless search of finding Castiel. After they greet, Dean asks if he is sane again, which Cas says he is, or in their case, as sane as he can be, seeing as he an angel in Purgatory. He then tells Dean that after their arrival in Purgatory, he actually ran away. This lead Dean to believe he left him to fend for himself. Shocked and disbelieving this notion, Castiel elaborated by telling him that he was surrounded by Leviathan and had to get them away from Dean to protect him. Dean firmly insisted that he would not leave Purgatory without him.

He appears in another flashback, where he is struggling to hold on to an arm, while it is unclear what the scenario is, Castiel shouts Dean's name as they are pulled apart.

In flashbacks in Blood Brother, Castiel, Dean and Benny come under attack by three monsters and Castiel kills one with his powers. Castiel and Benny try to convince Dean to let Castiel stay away from Dean because as a Seraph he is drawing monsters to him and the way out of Purgatory might not even work for him as he isn't a human or former human like Benny. However, Dean refuses to leave him behind and before they can argue anymore, Castiel senses Leviathans approaching them. Castiel is unable to teleport them out as the Leviathans are too close so they run, but are ambushed by two Leviathans. One manages to defeat Castiel, but before she can kill him, Benny decapitates her, saving Castiel to Dean's shock.

Castiel finally escapes Purgatory in A Little Slice of Kevin. He claims he could not remember how he escaped, a story not received well by a doubtful Dean. Castiel aids the Winchesters and Mrs. Tran in saving Kevin and retrieving the tablet from Crowley. He displays much of his previous abilities, but suffers observable fatigue after using them. After the confrontation with Crowley, Castiel reveals to Dean at the portal that he intentionally wanted to be left behind in Purgatory as a form of penance. Moments after, Castiel finds himself with in Heaven, with another angel. It is then revealed revealed that his escape was orchestrated by the angel Naomi, who sent an incursion that claimed the lives of several angels to aid the seraph. Much to his own surprise, Castiel casually reveals information about the Winchesters and the tablet under the simple request of Naomi. He is then sent back to earth without recollection of the meeting with Naomi.

Alternate Future - 2014
In an alternate post-Apocalyptic future in which Lucifer has ravaged the world with the Croatoan Virus, the Angels abandon Earth and Castiel loses his remaining powers (though he is still able to sense that the Present Dean is from the past). He joins the Future Dean's resistance movement against Lucifer, but quickly becomes bitter and depressed with the situation. As a result, he spends most of his time immersed in drugs and women.

Future Castiel participates in the failed attack on Lucifer at the end of the episode. He is presumably killed along with the rest of the Future Dean's group.

Powers and Abilities
Since his first appearance, Castiel possessed astounding abilities and was one of the most powerful beings the Winchester brothers have ever met at the time. Uriel seemed so sure of his powers that he felt confident that if Castiel joined him and his fellow rebels, they would be powerful enough to challenge Heaven and free Lucifer from his Cage. Even Anna, despite having once been Castiel's superior, chose not to directly confront him after Castiel appointed himself as the Winchesters' guardian, and instead went back through time in an attempt to ensure that Sam and Dean are never born. Even when not at full strength, he was shown to be a very capable fighter due to him killing several of his angelic siblings when he was fighting to prevent the Apocalypse. Castiel displayed the following powers when he was a mere angel, although he lost some when he fell as the powers came from Heaven:

Original abilities

 * Angelic Possession - Castiel needs to use a vessel while on Earth. As an angel, he requires the vessel's permission.
 * Astral Projection - Castiel is able to partially project his true form while inside his vessel, which appears as shadows of feathery wings.
 * Chronokinesis - Castiel can travel forward and backward in time, and he can take passengers.
 * Dream Walking - Castiel appeared in Dean's dream to deliver him a message.
 * Eidetic Memory - Castiel has the face and name of every prophet etched into his memory.
 * Healing - Castiel could instantly heal the wounds, diseases, and toxins of humans. Lost when he became a Fallen Angel the first time as the power came from Heaven but regained after second resurrection.
 * Immortality - Castiel as an angel doesn't age and is immune to disease. He never tires, and does not need to eat, sleep, drink, or breathe to sustain himself.
 * Invulnerability - As an angel, there are very few things able to kill Castiel.
 * Killing Touch - Castiel is able to kill lower-level demons and other beings like monsters with a simple touch. Lost when he became a fallen angel as it came from Heaven but regained a more powerful version after second resurrection.
 * Resurrection - Castiel brought Dean and Bobby back from the dead. Lost when he became a Fallen Angel as it came from Heaven but regained after second resurrection.
 * Sedation - Castiel can cause instant unconsciousness in humans.
 * Pyrokinesis - Castiel displays the ability to burn through ropes holding him.
 * Supernatural Strength - Castiel is physically stronger than humans, most demons and monsters. Although incredibly strong, a normal angel such as Uriel had a higher level of super strength. However, Castiel is very skilled in the art of battle with angelic blades, having defeated several angels at least as powerful as him simultaneously on many occasions.
 * Supernatural Perception - Castiel can see things hidden to humans.
 * Telekinesis - Castiel can impart kinetic energy on matter with his mind.
 * Telepathy - Castiel is able to read the minds of humans and lower-level angels.
 * Teleportation - Castiel can travel from one place to another instantly, without occupying the space in between.
 * Voice Mimicry - Castiel once perfectly imitated Bobby Singer's voice.
 * Protective Charm - Castiel is able to protect someone from harm beforehand, as seen when he prevented his vessel, Jimmy Novak from burning his hand on a pot of boiling water as a sign of faith.
 * Spell Casting - As an angel, Castiel has extensive knowledge of enochian symbols and spells which he has used for a variety of effects. He could draw an enochian devil's trap that could completely supress and bound a demon as powerful as Alistair. He also knew of symbols that could banish or ward off angels. After his first ressurection he branded Sam and Dean with a pattern of symbols that would conceal them from every angel in creation, even one as powerful as Lucifer.

Seraph abilities
After he was killed by Lucifer during the Apocalypse, God resurrected Castiel and endowed him with new powers. Castiel reveals in "Blood Brother" that he's now a Seraph, a higher form of angelic being. Not only has he gained greatly enhanced powers while retaining all previous ones, but now he is independent from Heaven. This means he retains his full powers despite being a fallen angel.

Following his rescue from Purgatory, Castiel appears weakened from his time in the monster realm as he is quickly drained from using his powers such as teleporting or killing a low-level demon. His new powers include:
 * Advanced Chronokinesis - Castiel now can send people back through time and bring them back without having to physically be there with them. However, the further back he sends someone, the harder it is to retrieve them. This was evidenced by the time he sent Sam and Dean to the 1800's, he could only send them for 24 hours or else he would be unable to bring them back.
 * Invisibility - Castiel can become invisible to humans.
 * Perception Manipulation -  By placing his hand on a person's forehead, Castiel is able to manipulate a person's mind, being able to create, erase or alter memories or simply alter their perception of events altogether. He is also able to show a person the true version of their memories, not just the version they choose to remember. He easily tore down the mental dam inserted by Death on Sam that protected him from the memories of him being tortured in Lucifer's Cage. Though he was unable to cure Sam from the resulting madness it caused, he was able to transfer it from Sam to himself.
 * Advanced Pyrokinesis - Castiel can now no longer just create fire, but he can manipulate and extinguish it effectively.
 * Reality Warping - Cas, in one instance, altered reality, by shaking a 'Sorry' board-game, and having everything instantly set up. He was later able to fill a vial with his blood just holding it tight in his hand and not making any cuts.
 * Enhanced Supernatural Strength - As a Seraph, Castiel has exibited higher levels of physical strength. He was capable of overpowering his angelic brethren with greater ease as seen against Raphael's soldiers or against his former friend Rachel. Though he could still be outmatched and killed by the Leviathans, Castiel proved capable of standing up against them. He was able to briefly restrain the Leviathan boss Dick Roman, after catching him off-guard, and in Purgatory managed to hold off two Leviathans, and ultimately incapacitate them with Dean's help.
 * Advanced Killing Touch - Castiel's angelic killing touch became much more powerful after his resurrection. He could instantly kill several demons with great ease by using this ability. He was also capable of killing various monsters using this ability such as Lenore, or other creatures even in Purgatory. He may even be capable of killing or at least harming a Leviathan, as seen in Purgatory when he tried to do this to one, and it quickly tried to evade the seraph's touch. However, more powerful beings such as the archangel Raphael, however, were immune to this power and could also extend this protection to lesser beings such as demons.
 * Advanced Healing - Castiel has displayed the ability to not only heal any wound, but can also cure people of infections that will turn them into monsters as shown when he cured Dean of his transformation into a Jefferson Starship. Castiel also believed he could heal Kevin Tran of a cut-off finger but his ability to do this is not yet confirmed.
 * Proficient Torturer - Castiel was shown to be skilled at the art of torture, as seen when he tortured one of Eve's Jefferson Starships into giving him information in a matter of minutes, despite having his powers blocked by the mother of all and on another occasion, when he tortured Dr. Visyak (who had previously resisted Crowley's atempts at the same) into giving him the spell to open Purgatory.
 * Soul Reading/Channeling - By pushing his hand into a person's chest, Castiel can determine the presence and condition of a person's soul, and if the soul was branded by a deal. He can also siphon energy from or completely absorb a soul to recharge and enhance his powers. The process is extremely painful and delicate, having been noted by Castiel as putting one's hand into a nuclear reactor and causing the person to explode shoud anything go wrong.
 * Leviathan Perception/Sensing - Due to having been used as a vessel for the Leviathans, Castiel can see past their vessels and shapeshifting abilities and correctly identify them. This ability allowed him to identify the real Dick Roman, so he and Dean could kill him. While in Purgatory, Castiel was able to sense the presence of two nearby Leviathans before they could attack the group while Dean and Benny were completely unaware of them and later sensed two more approaching as he and Dean neared the escape portal.
 * Enhanced Astral Projection - As a seraph, Castiel's true visage is now far more terrifying and hazardeous to creatures such as humans and demons. While projecting his true form from his vessel, his irises gained a deep blue glow, his body emitted a powerful white light and the shadows of his wings appeared on his back. Even in a weakend state, he was able to intimidate Crowley into retreat, despite the demon's position as the current King of Hell.

Soul-enhanced abilities
In order to fight the war against Raphael, Castiel made a deal with Crowley for a loan of 50,000 souls, which boosted his powers and allowed him to launch the first strike against Raphael, though he was still grossly outclassed by the Archangel. After absorbing the 30-40 million souls of Purgatory (including a large number of Leviathans), Castiel was endowed with god-like powers that made him both highly dangerous and unstable, due to the power intoxicating him and clouding his judgement. Death reffered to him as a mutated angel and that his vessel was eventually going to melt and explode.
 * Holy Light - Following a loan of 50,000 souls from Crowley, Castiel could emit a powerful white light from the palm of his hand in a similar fashion to that of an Archangel. He used this power to termporarily banish Raphael and killed at least a dozen Jefferson Starships at the diner he, Sam and Dean were being held. This ability apparently relies on his target having their eyes open as he yelled at Sam, Dean and Bobby to shut their eyes when he used it and they were unaffected as a result.
 * Angelic Power Negation - Cas is now capable of neutralizing even an archangel's powers, as seen when he prevented Raphael from teleporting away, sarcastically asking his older brother if someone "clipped your wings".
 * Molecular Combustion - By snapping his fingers, Castiel can speed up molecules to the point where it can cause an individual to explode. In an ironic twist, he killed the Archangel Raphael in this way, after having previously suffered the same death at the hands of his older brother.
 * Nigh-Omnipotence - After consuming the Purgatory souls, Castiel was able to project his desires into the physical or spiritual world(s) as he killed thousands in Heaven according to Hester. Castiel could kill humans in a variety of ways with a thought or word as well as perform miracles like making the blind see or curing an entire colony of lepers. Castiel even told Crowley of his intial intention to eliminate Hell, an entire spiritual realm. However Death was unconcerned by Castiel's newfound powers and openly mocked him. Notably, Castiel was concerned with keeping Michael and Lucifer in the Cage. Due to the short period of time Castiel held on to those the millions of souls, it is unknown how he would have faired against the archangels.
 * Invincibility - Due to his massive consumption of the Purgatory souls, Castiel became immune to nearly any form of harm as seen when he was unfazed from being stabbed in the back by an angel blade. Enochian signs were now useless against him as seen when he tracked down and cornered Crowley in his sigil-covered trailer. However, Death and God could possibly kill him.
 * Spell Negation - With a simple snap of his fingers, Castiel was able to break the spell that Sam, Dean and Bobby had cast to bind Death, something the latter was unable to do.

Death tally
Castiel has died three times over the course of the show, only to be resurrected by God each time. By "Survival of the Fittest", he believes his resurrections to be punishments rather than gifts, as things only get worse when he is brought back.
 * Imploded by Raphael (off-screen) in "Lucifer Rising".
 * Imploded by Lucifer in "Swan Song".
 * Died from the effects of containing multiple Leviathan in "Meet The New Boss".

Family

 * God - (Creator; Father)
 * Michael - Elder Brother; Former superior
 * Raphael - Elder Brother; arch-enemy
 * Lucifer - Elder Brother; enemy
 * Gabriel - Elder Brother
 * Zachariah - (Former Superior/Teacher)
 * Rachel - Lieutenant in the war against Raphael
 * Anna, Uriel, Balthazar, Hester, Inias - (Fellow Soldiers in his Garrison)
 * Other Angels - (Angelic brethren)
 * Sam and Dean - Surrogate brothers
 * Daphne Allen - Wife (as Emanuel)
 * Jimmy Novak - Vessel

Relationships

 * Dean and Castiel - Castiel and Dean's relationship.
 * Sam and Castiel - Castiel and Sam's relationship.
 * Minor Relationships - Castiel's other relationships he encounters.
 * Meg and Castiel - Meg and Castiel's relationship.

Season 3

 * "Red Sky at Morning" (name is invoked for a spell)

Season 4

 * "Lazarus Rising"
 * "Are You There God? It's Me, Dean Winchester"
 * "In The Beginning"
 * "It's the Great Pumpkin, Sam Winchester"
 * "I Know What You Did Last Summer"
 * "Heaven and Hell"
 * "Death Takes a Holiday"
 * "On the Head of a Pin"
 * "The Monster at the End of This Book"
 * "The Rapture"
 * "When the Levee Breaks"
 * "Lucifer Rising"

Season 5

 * "Sympathy for the Devil"
 * "Good God, Y'all"
 * "Free to Be You and Me"
 * "The End"
 * "I Believe the Children Are Our Future"
 * "Changing Channels"
 * "Abandon All Hope..."
 * "The Song Remains the Same"
 * "My Bloody Valentine"
 * "Dark Side of the Moon"
 * "99 Problems"
 * "Point of No Return"
 * "Two Minutes to Midnight"
 * "Swan Song"

Season 6

 * "The Third Man"
 * "You Can't Handle The Truth"
 * "Family Matters"
 * "Caged Heat"
 * "Like A Virgin"
 * "The French Mistake"
 * "My Heart Will Go On"
 * "Frontierland"
 * "Mommy Dearest"
 * "The Man Who Would Be King"
 * "Let It Bleed"
 * "The Man Who Knew Too Much"

Season 7

 * "Meet The New Boss"
 * "Hello, Cruel World"
 * "Shut Up, Dr. Phil" (seen in Dean's nightmare)
 * "The Born-Again Identity"
 * "Reading Is Fundamental"
 * "Survival of the Fittest"

Season 8

 * "What's Up, Tiger Mommy?" (seen in Dean's flashbacks of Purgatory)
 * Blood Brother (seen in Dean's flashbacks of Purgatory)
 * "A Little Slice of Kevin"