Jack Kline (Nephilim)

Jack (b. May 18, 2017) is the son of Lucifer and Kelly Kline. He is the first and only known Nephilim to be sired by an Archangel.

Season 12
After Lucifer took possession of President Jefferson Rooney, he had sex with Jefferson's aide and lover, Kelly, who was unaware of the possession. After their first round, Kelly said she believed Jefferson Rooney (Lucifer) would make a great father, which inspired Lucifer to sleep with her again and conceive a child.

The conception of the Nephilim was felt by Castiel, who was miles away inside the Men of Letters Bunker. He and the Winchester brothers decided they needed to get rid of the child, as it was the "spawn of Lucifer".

After Sam and Dean successfully re-imprisoned Lucifer, Castiel took Kelly away to a diner. He pleaded with her to get rid of the child, informing her that it was not Jefferson's, but the Devil's. Kelly excused herself to the bathroom and fled the diner. As she rode away in a taxi, she insisted through a phone call that the baby was still hers, and she did not want to get rid of it.

After his mother was rescued by Dagon from angels trying to kill her and him, Dagon revealed to his mother Kelly that he was a boy. Elsewhere, Lucifer mentioned to Crowley that his son's power is a chip off the old block. When Kelly began experiencing "weird little pains", she ordered Dagon to take her to a doctor, in case something was wrong with the baby. Dr. Turner could not find anything wrong with the baby itself, and Dagon ensured Kelly that the child was fine and he was going to become big and strong. The pains were in fact the start of intense, life-threatening pain that Kelly was going to experience, since birthing a Nephilim was always fatal to the human.

In The Future, Kelly only has less than a month left before she gives birth. Kelly is told by Dagon of the unimaginable horror the child will unleash upon his birth. In an effort to stop this, Kelly commits suicide only to have her child resurrect her. Following her resurrection, Kelly states that she felt his soul surge through her and that it was good, not evil though Dagon believes the child only brought her back to ensure his own survival.

After being kidnapped by Castiel, Kelly insists on the goodness of her child. Castiel is ordered by Joshua to bring Kelly through the portal to Heaven which will kill both Kelly and her child and scatter their atoms across the universe. As Kelly continues to insist on her son's goodness, Castiel asks her about if this is true, who will guide and protect the child after his birth since Kelly will die in the process. The child kicks moments later and Castiel feels it. As the Winchesters arrive, the child has a premonition of a conflict between Dagon and Castiel at Heaven's Portal and instructs Kelly to take herself and Castiel there, having chosen Castiel to protect and guide him after sensing Castiel when he touched Kelly's belly.

At Heaven's Portal, Dagon kills Joshua and effortlessly defeats Kelly's defenders. As Castiel and Kelly stand hand-in-hand, Jack empowers Castiel, causing his eyes to glow. With the child aiding him, Castiel is easily able to overpower a shocked Dagon and negates her powers. Telling Dagon to "call it a miracle", Castiel uses Jack's power to incinerate the Prince of Hell.

Following Dagon's death, Castiel tells the Winchesters that it was both himself and Lucifer's child who killed Dagon. Castiel tells the Winchesters, who planned to remove the child's grace and leave him human and powerless, that he now knows that the child must be born with all of his power intact as he now has faith in the child's goodness. As they depart in his truck, Castiel tells Kelly that the child showed him "the future".

Castiel takes Kelly to a lakeside house which is set for a newborn baby. Kelly is desperate for her son to be born good and well-loved. During labor, a portal to another dimension is opened and Team Free Will use it to trap Lucifer within but he drew Mary with him as they tried to push him in. Sam returns to the house to find Kelly dead, along with a trail of scorched foot prints leading to the nursery. Inside, he discovers a full grown Nephilim with golden eyes sitting in the corner, and gives Sam a menacing smile.

Season 13
In Lost & Found, Sam tries and talk to Jack, who asks if he is his father. Sam tells Jack he is not his father, and is still attempting to speak with Jack when Dean arrives and shoots at Jack, narrowly missing him after Sam tried to stop him. Jack becomes angry and in self defense begins screaming, causing a pulse of energy to emanate from his body that blows out all the windows in the house and freezes Sam and Dean in the air before jettisoning them back into the wall, knocking them unconscious. Jack leaves the house and wanders the woods until he comes across a Pirate Pete's Jolly Treats, and asks at the drive-thru for his father. Seeing that he is naked and confused, an employee, Clark Barker, calls his mother, Sheriff Christine Barker, to deal with the situation. Sheriff Barker arrives to find Jack still standing in the parking lot. Seeing the sheriff's gun, Jack initially takes a defensive stance until Sheriff Barker assures him she only wants to help him. At the Sheriff's Department, a now fully clothed Jack begins absorbing his new surroundings while Sheriff Barker tries to get information out of him. Jack is only able to tell her that his mother is in Heaven and that he is looking for his father. Jack is then fingerprinted, and sits with Clark who asks what Jack is on. Jack tells him he isn't stoned, but that he is hungry. Clark takes Jack to the break room, where Jack tests out a new power that allows him to get free food from the vending machines; he becomes a big fan of nougat. Soon after showing this ability to Sheriff Barker, Jack begins picking up angel radio, which causes him debilitating pain. When Sheriff Barker tries to stop him from leaving, Jack loses control and sends her flying into the vending machines. As he tries to leave the station, he comes face to face with Dean, but before Jack can do anything Sam hits him with a taser, rendering Jack unconscious.

Sam and Jack are placed in a holding cell, while Dean explains the situation to the sheriff. When Jack comes to, Sam apologizes to Jack and explains he didn't want to hurt him. Jack tells Sam he was scared of the voices he was hearing, which caused him to lose control. Jack tells Sam that he doesn't know if he can open another rift, and that he needs to find his father, who will protect him. When Sam tells him Lucifer doesn't do that, Jack corrects him and tells him that Castiel is his father, because his mother told him that Castiel would keep him safe. He also explains that through his mother, he knew the world was dangerous and had to mature into adulthood immediately after his birth to protect himself.

A trio of angels led by Miriam arrive at the station; two of the angels are able to locate Jack in the holding cell area. When they try to take him, a fight ensues, ending with Sam banishing them. The action of the sigil causes Jack momentary discomfort. Miriam enters the holding cell area but is flanked by Sam and Dean. Feigning that she is giving up, she tells Sam that if the angels can't have him, no one will and drives her angel blade into Jack's heart. After Sam kills her in retaliation, Jack drops to his knees and pulls the blade from his chest. To all their astonishment, he is fine.

In the aftermath of the clash, Sam and Dean decide to take Jack with them back to the Men of Letters Bunker, but before going home, the trio go and give Castiel and Jack's mother Kelly a hunter funeral pyre.

In The Rising Son, Jack spends his time with Sam and Dean Winchester. Jack notices that Dean doesn't particularly like him and tries to emulate him in order to appear more favorable. Jack eats a burger and drinks beer the same way (and the same time) as Dean does, but this only serves to annoy Dean. The trio are soon visited by Donatello Redfield. Donatello notices that Jack isn't human and admits that he himself no longer has his soul. Later on, he is told by "Donatello" to use his powers to open a rift, but just as he nearly completes it Dean, Sam and the real Donatello appear. Jack realizes he was tricked by Asmodeus who attacks his friends causing him to get angry and attempts to attack Asmodeus but the latter flees. During the night, Dean approaches Jack and tells him that while he is unsure of being evil if he turns then he will be the one to kill him.

In Patience, Sam has Jack practice his powers to move a pencil with his mind which he struggles with and becomes irritated that he can't do one good thing right. Very soon, he is able to move the pencil and tells Sam of his feat taking the latter's congrats in stride as he mentions Dean's promise to kill him but Sam says he won't allow it.

At night, he overhears an argument between Dean and Sam where he hears Sam defending him and Dean accusing Sam of using him to bring back their mother. He then hears Dean state he was the cause of Castiel's death which causes his eyes to glow as he says the angel's name. This act unknowingly sends a telepathic message to Castiel in The Empty and he awakens after hearing Jack's voice.

In The Big Empty, Jack is watching videos on the computers before he is invited by Sam to join him and Dean on an mission though he refuses due to Dean's distrust of him while also revealing he is aware Sam wants him to control his powers to save his mother.

Sam confirms he wants to save his mother but states he does care for Jack and promises not to allow Dean to hurt him as they go off to their quest.

The trio go to the victim's house where they put on their aliases as FBI, which confuses Jack, and ask the neighbor about what she saw and she explains it was definitely her old neighbor's wife. Dean and Sam begin making deductions on what could of it done it as they decide to visit the dead woman's grave. They burn the body to ensure it's not a zombie and tell a curious Jack they did so for his mother and continue to ponder on what did it.

Sam then returns and holds her at gunpoint revealing he discovered Mia is a Shapeshifter as Dean joins him in pointing a gun.

Mia states she did not hurt anyone as the brothers tell her that some of her patients have ended up dead which surprises her. Knowing they are hunters, Mia proclaims her innocence and tells them she has an alibi and to check it out to confirm it.

Dean goes to do so and returns confirming she is telling the truth, to her relief. They then ask if she isn't killing anyone who was as she deduces it to be her old lover Buddy who is also shifter and enjoyed killing just to torment others. However, she is trying to atone for her past by helping people get through their grief. Understanding, the Winchesters state if Buddy is doing so then he must be taking on forms of her patients to get information and kill them.

Dean and Jack go to a possible lead, as Sam stays with Mia before he leaves in Mia's car to pursue him.

Dean and Jack return soon after and while Dean calls Sam, Jack speaks with Mia and tells her that he is not actually Sam and Dean's brother and that his mother actually died when he was born. He shows her the video of his mother and asks Mia if she will take on Kelly's form for him to gain some closure.

Seeing his pain, Mia agrees and shifts into the form of Kelly while Jack has his eyes closed. Mia, as Kelly, then comforts Jack about his self-doubt. Dean suddenly barges in and knocks out Jack before holding Mia at gunpoint. This Dean reveals himself to be Buddy.

Buddy ties up Dean and Jack while speaking to Mia, angry that she abandoned him to start a new life. He proclaims his intention of destroying that life by having her kill the hostages but she refuses and tells him to kill her.

Just as he's about to shoot, Buddy sees Sam return and readies to kill him by tricking him into coming to him. When Sam starts to open the door, Mia tries to stop Buddy but is pushed aside. Buddy shoots at Sam, but Jack uses his power to cause the bullet to ricochet into the wall. This saves and allows Sam to shoot Buddy, killing him.

Mia apologizes for the trouble she has caused and promised to do something about Buddy. She laments that all her attempts to help people were for naught but Jack states she helped him in his time of need. This somewhat relieves her spirits as she smiled at him in thanks.

At the bunker, Dean meets Jack and congratulates him on his actions in the mission as Jack accepts it with a smile.

In Tombstone, Jack goes over cases on the computers just as Dean and Sam return to the bunker with Jack questioning how their case went before noticing their strange behavior as they reveal a resurrected Castiel. Jack is surprised as he brings up the brothers' statement of nothing coming back from being burned but soon hears it is partly because of him begging for the angel's return is why he has come back. Excited by this, Jack greets the newly resurrected Angel with a hug and proceeds to tell everyone he found a case. Despite it seeming like Dean is humoring him, it turns out that the grave robbery was a real case just not a zombie like Jack thought but rather a Ghoul. Jack also deduced the ghoul's identity as the mortician's boyfriend from a picture he had seen there.

After tracking the ghoul to a bank, a gunfight breaks out. In an attempt to stop it, Jack unleashes a telekinetic blast that throws the Ghoul and a security guard back. The security guard hits his head on a pole and dies. Jack seems to be struggling with the fact he has killed someone and is sent back to the bunker. While Sam and Castiel attempt to console him and tell him that he just made a mistake Jack seems to be taking it harder than the others realize. Once Dean returns, he explains he had the ghoul take the fall of the guard's death as Jack has an outburst regarding the dead man and is scared that he will hurt the others saying the they are all he has and he can't hurt them. Jack throws them back saying he is sorry and teleports out of the bunker.

In War of the Worlds, the Winchesters and Asmodeus attempt to find Jack who has managed to cloak himself from Asmodeus' detection. After escaping from the alternate reality, a weakened Lucifer tells Castiel that he needs Jack's help to defeat the alternate reality Michael. Lucifer also learns Jack's name from Castiel and seems impressed. At the same time, the Winchesters put out an APB with every hunter they know for Jack and have Sheriff Jody Mills put out a police APB at the same time. After capturing Lucifer and Castiel, Asmodeus also became aware of the invading Michael, stating if it was true he needed Jack on his side.

In The Scorpion and The Frog, the Winchesters continue their search for Jack. They are approached by the King of the Crossroads Barthamus who offers a Nephilim tracking spell to find Jack in exchange for the Winchesters helping him to steal back his bones from Luther Shrike.

Ultimately, the tracking spell is destroyed when Alice burns Barthamus' bones to kill him, resulting in Barthamus being consumed in flames. Though they lost their chance to find Jack, the Winchesters are pleased with the outcome as they stopped Barthamus and saved Alice from her deal.

In The Bad Place, Jack is revealed to have been learning to control his powers and attempting to prove that he is good by locating and rescuing Mary Winchester for Sam and Dean since he knew they missed her. However, while he has been able to feel the alternate realities, he lacked the ability to actually see them and so could not open a rift. Using what the Winchesters taught him, Jack does research and learns about dreamwalkers who have the ability to see into other worlds.

In an attempt to rescue Mary, Jack contacts dreamwalker Derek Swan. Jack is able to convince Derek to help him try to open a rift into the alternate reality. As Derek uses his powers to search for the correct reality, Jack telepathically connects with Derek's mind to see what Derek sees for himself. Though the two manage to find Mary, Derek is not strong enough to hold the connection long enough for Jack to open a rift. Jack stops before he can seriously hurt Derek and Derek points Jack to Kaia Nieves who is the most powerful dreamwalker Derek has ever met. Derek is also able to give Jack a suggestion on the best place to attempt to open the portal.

Shortly afterwards, angels looking for Jack torture and kill Derek. Derek's murder is discovered by Sheriff Jody Mills who learns that Derek's girlfriend saw Jack shortly before Derek's death. After getting confirmation that Jack was who the girlfriend saw, the Winchesters come to the wrong conclusion that Jack murdered Derek and is now looking for Lucifer.

Jack is able to track Kaia to a drug treatment facility and at first claims to be there for a cocaine addiction. Jack eventually admits that he needs Kaia's help and offers to help Kaia escape in exchange. Subduing a doctor, Jack is able to help Kaia escape through a triple-locked door. However, Kaia refuses to help Jack and runs off while the Winchesters finally catch up to him. Jack is surprised to learn that Derek is dead and explains what he was really up to, telling them he learn to control some of his powers. He then shows them the vision Derek saw of their mother.

Jack joins the Winchesters in searching for Kaia, but is shocked to realize that they had believed him to be Derek's killer. When they explain that they believed him to be searching for Lucifer, Jack explains that Lucifer is nothing to him and that the Winchesters and Castiel are his family. Dean agrees with the sentiment and praises Jack's efforts to rescue Mary.

As they search for Kaia, Jack learns from "angel radio" that the angels have kidnapped Kaia. The Winchesters and Jack manage to capture the male angel who, along with a female angel, is attempting to lure Jack in in the hope that he can help them create more angels. Jack refuses and when the angels attack, telekinetically blasts the female through a glass window and a brick wall. As the male attempts to kill Dean, Jack forces the male angel with telekinesis to stab himself with his own angel blade, killing the angel.

After the rescue, Kaia continues to refuse to help the Winchesters and Jack due to her fears of The Bad Place. Desperate to save Mary, Dean forces her at gunpoint to join them. As they make their way to the location suggested by Derek, Jack offers to show Kaia what Derek saw so that she can see that its not all bad. Kaia agrees and Jack telepathically connects with her and shows Kaia Derek's vision, gaining her cooperation.

As they drive, the Winchesters, Kaia and Jack come under attack by the female angel and six others. The group flees onto a ship where they put up angel warding, but the angels combine powers to begin destroying it. Though Jack has the power to defeat the angels, he realizes that they will use "angel radio" to cause him debilitating pain and capture him. At Kaia's suggestion, she and Jack combine powers in an attempt to open a rift to Mary. Telepathically connecting to Kaia, Jack guides her in moving away from the Bad Place and to Mary. As the angels break through the wards, Jack and Kaia find Mary and Jack begins opening a rift. However, Kaia flashes between Mary and the Bad Place. Finally, with a scream from Kaia, the two emit a yellow glow that opens a rift and sends out a wave of energy that disintegrates the attacking angels.

Due to Kaia flashing between Mary and the Bad Place, the group ends up separated from each other. Kaia ends up on the side of the road while the Winchesters are transported to the Bad Place. Jack arrives alone in the alternate reality and wakes up at the feet of Mary who is trapped in a small metal cage. As Mary stares at Jack in confusion, Jack looks at Mary's predicament with worry.

In Wayward Sisters, as Kaia and Claire Novak rescue the Winchesters from the Bad Place, Sam asks about Jack. Kaia tells Sam that she thinks Jack ended up in "the other place" with their mother.

During Devil's Bargain, the Winchesters are informed by Castiel about Michael and realize Jack as well as Mary are in danger. They seek out Donatello to read a tablet to find a spell that would open a rift to the other world to save them before Michael invades. Asmodeus (while disguising himself as Castiel) got some information about Jack's location from Donatello.

Powers and Abilities
As a Nephilim, Jack is one of the most powerful beings in Creation; however as the son of a human and an archangel, Lucifer himself, Jack’s power far exceeds that of any Nephilim. It has been stated numerous times that Jack possesses unimaginable power and according to his father, his power is "a chip of the old ball of heavenly light". Doctor Hess claimed the child could destroy the whole universe. The Angel Miriam stated Jack could do "almost anything". The prophet Donatello, who has been in the presence of God, Amara, and Lucifer, initially mistook Jack for God when sensing his power, as it was "not dark, not toxic", unlike Lucifer's, yet still very powerful. Even before he left the womb, Jack was able to grant Seraph Castiel the power to effortlessly overpower and incinerate Prince of Hell Dagon and force Prince of Hell Asmodeus to flee when enraged. It was eventually revealed that, according to Nephilim lore, Nephilim become stronger than the angel who sired them, meaning Jack will eventually become more powerful than Lucifer himself, his angelic sire. His power is so great he was able to awaken Castiel, who had been sent to The Empty, a place even God has no power over. Most recently, Asmodeus described Jack as a entity of immense power, and the angels state Jack may be powerful enough to produce new angels, something that hasn’t been done since God created the original angels. Following his use of telekinesis to stop Buddy, Jack gains a greater control over his powers, particularly telekinesis. In The Bad Place, Jack has a more advanced control and use of his powers after practicing with them.
 * Healing - From the womb, Jack was able to heal Kelly Kline's slit wrists and massive blood loss. While empowering Castiel, he also healed the angel's injuries from the fight with Dagon in a matter of seconds.
 * Resurrection - At the same time he healed his mother's injuries, he resurrected her. However, Miriam indicated that, despite his vast power, Jack is not powerful enough to resurrect Castiel as he is "all the way dead".
 * Precognition - Jack, from the womb, was able to see a vision of the confrontation between Castiel and Dagon at Heavenly Portal which he was able to share with Kelly.
 * Power Granting - From the womb, Jack was able to temporarily empower Castiel to the point that he was able to overpower and kill the Prince of Hell Dagon.
 * Super Strength - While empowering Castiel, he granted him enough levels of superior strength to effortlessly overpower the Prince of Hell Dagon, who had easily beaten Castiel while he was only using his seraphim powers.
 * Power Negation - While empowering Castiel, he granted him the power to render Dagon completely powerless.
 * Advanced Pyrokinesis - While empowering Castiel, he granted him the power to burn Dagon, the Prince of Hell, to ashes, a feat previously unseen with any other character.
 * Reality Warping - Under the influence of a disguised Asmodeus, Jack was able to open a Hell Gate to release the Shedim. However, this required Jack's full concentration and when his concentration broke, the Hell Gate closed.
 * Portal Creation - Jack's birth was able to open a rift into an alternate reality. Jack later experimented in attempting to open a door to rescue Mary from the alternate reality, but determined that while he could feel around, he needed a dreamwalker in order to be able to see the realm. When combining his powers with Kaia like this, due to her flashing between Mary and the Bad Place, Jack transported everyone to three different locations: Kaia to a roadside, himself to Mary and the Winchesters to the Bad Place. This effort also opened a rift to the Bad Place though not to Apocalypse World.
 * Electrokinesis - Jack's labor caused a power outage. In his normal state, he also able to effect the works of machinery and electricity, such as lamps and a vending machine. When scared, he also can cause electricity to go haywire.
 * Terrakinesis - When Jack becomes enraged at Asmodeus harming the Winchesters and Donatello, his anger causes the ground to shake.
 * Rapid Aging - Soon after birth, Jack willingly accelerated the natural aging process of his body to quickly become a young adult.
 * Telekinesis - Jack was able to send out powerful blasts of telekinetic energy strong enough to knock two people unconscious at once. When Jack did this, visible waves of energy emanated out of him. In a moment of pain, Jack accidentally threw a tattoo artist across a room. This happened without the visible waves of energy, indicating that Jack can use both forms of telekinesis. In order to save Sam's life, Jack blasted Buddy across a room with a telekinetic blast emanating from his hand while deflecting a bullet just by looking at it. Following this, Jack gained control of his telekinesis, using it to levitate a pencil and creating a small shock wave to knock Sam, Dean and Castiel out. However, when Jack attempted to use it to help against Dave Mather, he accidentally caught a security guard in the blast as well and killed him. When Jack uses his ability to produce a blast or shock wave his eyes glow gold but not when he used it in a more controlled manner like when he lifted the pencil. When confronted by two hostile angels, Jack was able to hit one with a telekinetic blast so hard she went flying through a glass window and then a brick wall. He was also able to force another angel to stab himself with his own angel blade.
 * Teleportation - Jack displayed the ability to teleport after being upset by a conversation and wanting to be away from it. He was later able to use this ability leave the Men of Letters bunker on purpose. When he teleports, Jack is shown to have the sound of wings flapping like an angels.
 * Telepathy - Jack showed the ability to telepathically call out to Castiel who could hear Jack even in the Empty. Even the Cosmic Entity was surprised how could something wake Castiel in his domain. Later, by touching his hands to Derek Swan's head, Jack was able to see everything that Derek saw with his powers. However, using this power on Derek caused the veins in his face to glow. Jack later used this ability in the same way to show the Winchesters and Kaia Nieves what Derek had seen of the alternate universe and their mother.
 * Enhanced Stamina - Jack once stated that he does not sleep a lot, but unlike an Angel still requires sleep.
 * Supernatural Concealment -  When Jack does not want to be found, his powers are subconsciously concealing him from other supernatural beings. This was shown by the fact that Asmodeus was incapable of tracking his whereabouts.
 * Invulnerability - Unlike other Nephilim, Jack is completely invulnerable against an angel blade. Jack had stabbed himself in the chest several times with a butcher knife and not die as such damage would kill any ordinary human. However, Jack can still feel pain, as shown when he flinched and reflexively threw a tattoo artist because of the pain from the needle. He can also be knocked out and injured by blunt force trauma to the head as any ordinary human.
 * Immunity - Despite his angelic heritage, Jack is immune to angel banishing sigils when not even his father Lucifer is immune to the sigils. He was also immune to angel warding.
 * Regeneration - He was able to easily remove an angel blade from his chest and quickly healed the wound in seconds. After getting two tattoos, both healed in seconds to the point that there was no sign that they had ever existed. After Jack stabbed himself several times in the chest with a butcher knife, his wounds healed in mere moments.
 * Sedation - Like an angel, Jack can put a person to sleep with just a touch.
 * Super Strength - Jack possesses inhuman strength sufficient to rip off the doorknob of a door that was triple-locked without even realizing.
 * Molecular Combustion (combined with Kaia Nieves) - When Jack and Kaia combined powers to open a door to an alternate reality, Kaia's screams caused them to emit a glow that caused six nearby angels to turn to dust.

Weaknesses

 * Heavenly Portal (possibly) - Due to Jack possessing a human soul, the angels believed that taking him through the portal while Kelly was pregnant with him would effectively destroy Jack. Later on after Jack teleported away from the bunker to protect the Winchester and Castiel from himself, Castiel asked Duma if Jack was in Metatron's old cell in Heaven as he believed that the angels have taken him.
 * Electrocution - Sam was able to render Jack unconscious with a taser blast.
 * Angel Radio - Hearing the angels communicate over "angel radio" caused Jack debilitating pain.
 * Grace Extraction (possibly) - It is believed by the Winchesters that by extracting Jack's grace, they could remove his powers and leave him a regular human.
 * Blunt Force Trauma - Buddy was able to knock Jack unconscious using a fireplace poker.

Personality
While still in his mother's womb, Jack was shown to be aware of his surroundings. He glanced at Dr. Turner during an examination and actively chose Castiel as his new protector and guide, replacing Dagon and even going so far as to help Castiel kill Dagon.

Since his father is Lucifer, it is a general assumption that Jack is the embodiment of pure evil. This belief was originally shared even by his mother, who attempted suicide so that her child wouldn't be unleashed upon the world. Jack resurrected her, however, saving himself in the process. Kelly then became convinced that Jack could be good, and that the world needed him. Eventually, Castiel also became hopeful that Jack could bring peace. He claimed that he was shown a vision of a future without pain, fear, or suffering.

Upon delivery, the baby rapidly ages and leaves his dead mother on her bed while he retreats to his nursery. When Sam discovers him, Jack is now an adult and smiles menacingly at the hunter.

Immediately after being born, Jack began searching for his father and showed great confusion at the world around him. All that he appeared to know was that his mother was in Heaven and his father was supposed to be waiting for him, but nothing beyond that. While Jack possessed memories from while he was in the womb, he didn't appear to understand what they meant. Jack was shown to enjoy some simple pleasures such as eating junk food with Clark and using his powers to get them some more. Jack has taken to using the computer more often after Sam showed him how to use it and mostly watches videos or plays games.

Because of his own heritage, Jack is somewhat sympathetic to those like him (mistaken to be evil monsters) as he connected with Mia Vallens, a shapeshifter who tries to help people. Jack comforted her after she expressed sadness that she wasn't able to help anyone and she accepted his words. Jack later told Kaia Nieves, a dreamwalker there were more use to her powers as he helped her see other worlds besides the one she has seen.

After accidentally killing someone, Jack was devastated by his actions and left the Winchesters and Castiel because he was afraid he would hurt them. This act also motivated him to go out on his own and master some of his powers to prove he is good.

Jack was shown to see Castiel as his father instead of Lucifer due to what Kelly had told him about Castiel. After Castiel was resurrected and Jack met him, he was very to excited to see him and hugged his uncle. He also declared that he only sees the Winchesters and Castiel as his family and states that his biological father Lucifer as well as the angels, his other uncles and aunts were nothing to him due to their ways. His words are supported by the fact that he protected Sam from being killed by a shapeshifter and saving Dean from being killed by  angels. Jack even mastered his powers to see other worlds to locate Mary Winchester for her sons to bring her back to them.

Physical Appearance
Upon birth, Jack took on the form of a Caucasian human young adult with dark brown hair. Unlike any other being seen on the show, Jack's eyes glow gold. They often glow when Jack uses his powers.

When Sam discovered Jack hiding in the corner of the room, he was visibly frightened by Jack's somewhat creepy appearance. After he encounters Sheriff Christine Clark, Jack obtains an outfit.

Relationships

 * Jack's Relationships

Appearances

 * Season 12
 * LOTUS
 * Stuck in the Middle (With You)
 * Family Feud
 * Somewhere Between Heaven and Hell
 * The British Invasion
 * The Future
 * Twigs & Twine & Tasha Banes
 * All Along the Watchtower
 * Season 13
 * Lost & Found
 * The Rising Son
 * Patience
 * The Big Empty
 * Advanced Thanatology
 * Tombstone
 * War of the Worlds
 * The Scorpion and The Frog
 * The Bad Place
 * Wayward Sisters
 * Breakdown
 * Devil's Bargain
 * Good Intentions

Trivia

 * Jack's name is a medieval diminutive of John. Jack was used as a slang meaning "man". John, on the other hand, means "Jehovah has been gracious".
 * In the initial drafts for the pilot episode, John Winchester was originally named Jack. This had to be changed when a real Jack Winchester was found to be living in Lawrence, Kansas.
 * Another possible meaning for the name Jack, is "Godly".
 * He is the second known Nephilim in the series, the other being Jane.
 * Coincidentally, both of them have a 4 letter name that starts with J.
 * He is also the first known offspring of an Archangel.
 * He is the first and only known being to possess golden eyes and golden grace.
 * Jack's golden grace shares its color with Lily Sunder's powers, and the color Castiel produced when he borrowed energy from Bobby Singer's soul. In both instances, angel grace was mixed with a human's soul. This is due to Jack being the embodiment of a human soul and an angel's grace bound into one.
 * However, his paternal cousin, Jane, has grayish grace.
 * Just like Lucifer, his father, he is immune to angel blades.
 * Sam had a misconception that The Antichrist was the child of Lucifer because of what he learned from the lore, but Castiel corrected that misunderstanding by revealing that Jesse Turner who was a half demon hybrid was the actual Antichrist in I Believe the Children Are Our Future. It wasn't until seven seasons later that the actual child of Lucifer would be conceived.
 * According to Sam, Nephilim don't require nine months to be born, and he was born on May 18th which corresponds to All Along the Watchtower, Season 12's finale.
 * When empowering Castiel and showing Kelly Kline a premonition, their eyes briefly glowed gold.
 * He bears similarities to The Source's Heir from Charmed. Both are the unborn child of the show's version of or equivalent to the Devil, both are able to channel their powers from the womb and both play a role in the deaths of a powerful, apparently unstoppable demon, Dagon in the case of and The Tall Man in the case of the Source's Heir. Both demons were also killed by a powerful fire ability that incinerated them.
 * Andrew Dabb referred to Jack as someone with an "evil source", but he was technically a "blank slate".
 * In Lost & Found, Dean refers to Jack as "Damien." This is a reference to the Antichrist from The Omen series of movies.
 * In LOTUS, Lucifer and Jack's mother, as a result of carrying Lucifer's child, were both seen incinerating bibles on physical contact since Nephilim share similar traits to their angelic sire.
 * However in The Rising Son, Jack is seen reading and touching a bible without burning it on contact.
 * Due to either his human or Archangel heritage (or perhaps both) Jack is capable of tasting like a human, instead of angels and seraphs, who taste on molecular level. This suggests that Jack's senses are developed beyond human, but not overdeveloped like those of an angel.
 * According to Andrew Dabb, he is about three months old as of the Season 13 episode Wayward Sisters.