Archangels

Archangels are extremely powerful celestial beings that were created by God. Being imbued with immense power and authority, they possess unspeakable power. They were made before the other angels, and basically everything else in creation, being born in this order: Michael, Lucifer, Raphael and Gabriel. It has been insinuated that the four archangels are the four angels that Anna describes that have seen God. Their true visages prove destructive and overwhelming to mortals and prove fatal in almost all instances. Most mortal vessels can't properly contain them, and because of this, they require their true, predestined vessels in order to stay within a vessel for as long as needed because other vessels will eventually decompose and degrade from the essence of an archangel. Castiel pronounces them as being fierce and absolute, but not very just. Michael and Raphael are tethered to prophets, and will intervene when a prophet is in danger and or when one tries to manipulate prophecy. All archangels possess abilities inherent in all angels but at an elevated level, and possess other, more special abilities that angels are incapable of using. The archangels are all immortal.

Known Archangels

 * Michael - Trapped in Lucifer's Cage
 * Lucifer - Trapped in his Cage
 * Raphael - Deceased
 * Gabriel - Deceased

"Tall Tales"
The Winchesters first encountered an Archangel back in Season 2 but never found out he was an Archangel until Season 5, They just believed it was a Trickster but it turned out to be Gabriel.

"Mystery Spot"
They Meet the same Trickster again in this episode where he plays a cruel joke on Sam by killing Dean over 100 times, but eventually they still never figure out he was an Angel/Archangel, they didn't even know they existed.

"The Monster at the End of This Book"
This episode marks the first actual contact with an Archangel, although not actually seen on screen only as a beam of light, this is the first time Sam and Dean find out about Raphael the Archangel.

"Lucifer Rising"
In this episode 2 Archangels are seen! The first is when Raphael destroys Castiel. The Second is when Lucifer is raising from the pit.

"Sympathy for the Devil"
In this episode the Archangel Lucifer finds his vessel.

"Free to Be You and Me"
This episode shows Raphael with his first physical human vessel, in which he gets caught within holy fire.

"The End"
In this episode Lucifer seems to have taken over Sam's body and is in control of the Earth and has gotten Sam to say Yes. (Alternative Future)

"Changing Channels"
This shows Dean and Sam the trickster was an Archangel all along after Sam and Dean realise the only time people get annoyed so bad is when they're talking about there own family which gives the Archangel Gabriel's disguise as the Trickster away.

"Abandon All Hope..."
Lucifer is the Archangel in this episode, and he is in Missouri getting ready for a ritual to bring back Death.

"The Song Remains the Same"
This episode marks the first time the Archangel Michael has a human vessel, he got John to say yes as he would save Mary's life.

"Point of No Return"
Michael appears in this episode but only as a beam of white light with Adam in the room with him suggesting he possessed Adam in this episode.

"Hammer of the Gods"
Gabriel resurfaces along with Lucifer, this shows the first Archangel Blade, which is used when the two brothers fight, and Lucifer ends up killing Gabriel.

"Swan Song"
Michael and Lucifer fight in this episode with Sam as Lucifer's vessel and Adam as Michaels, but Castiel uses some sort of holy fire molotov to send Michael away temporarily, Lucifer obliterates Castiel, and then kills Bobby, then intends on killing Dean, but Sam takes control of his body and opens Lucifer's Cage and pulls his self and Michael into it then it is locked.

"The Third Man"
Raphael beat Castiel and just as he was about to kill him(using what possibly could be Raphael's Archangel Blade or an Angel Blade) Balthazar came and destroyed his vessel using Lot's Salt. Raphael now has to find a new vessel.

"The French Mistake"
Shortly after the destruction of his former vessel Donnie Finnerman, Raphael creates a raging rain storm near Sioux Falls, South Dakota with his mere essence, as he seeks out a new suitable vessel to take over. After claiming his vessel, he pulls Sam and Dean from an alternate Earth and prepares to kill them and Balthazar but Castiel appears and sends him away because he now holds God's Weapons which scares the Archangel.

"The Man Who Would Be King"
Raphael, in his old vessal, appears in Castiel's flashback trying to convince Castiel to help him jump-start the Apocalypse. Castiel is brought before Raphael who is residing in Eron's CEO's heaven. When Castiel refuses, Raphael beats Castiel up and gives him an ultimatum. Castiel returns, and starts a civil war with Raphael.

"The Man Who Knew Too Much"
Crowley teams up with Raphael due to Castiel's double crossing. Raphael is going to take some of the souls but not all of them. Just as long as Castiel doesn't get them. When the perform the ritual, it doesn't work, due to Castiel giving them dog blood instead. When Castiel returns hes more powerful and kills Raphael.