Destiel

Destiel is a relationship between Dean Winchester and Castiel.

Season 4
Castiel first physically appears when Dean summons Castiel to a barn where he and Bobby Singer have all kinds of traps around the room; however, the traps and guns that Dean and Bobby use have no effect on Castiel. Dean asks Castiel what he is, Castiel answers that he is an angel of the Lord. Dean initially refuses to believe this, though he eventually comes around. Castiel is next seen when he comes to Dean after the rising of the witnesses. Dean asks why the angels didn't come to help, and Castiel responds by saying angels have better things to do than "perch on your shoulder".

When Dean continues to be rude, Castiel loses his temper, and tells Dean that, he should show him some respect because as Castiel was the one who took Dean out of Hell, Castiel can just easily change his mind and throw him back in.

When Dean continues to be rude, Castiel loses his temper, and tells Dean that, he should show him some respect because as Castiel was the one who took Dean out of Hell, Castiel can just easily change his mind and throw him back in.

Castiel comes to Dean later on and says, "You have to stop it." He sends Dean to the past, leading Dean to assume that he has to kill the Yellow-Eyed Demon. When he fails, and in fact indirectly assists in the future being set, Castiel takes him back to the future, and uses the experience as an example of destiny. He then looks into his eyes and professes his undying love for him.

Castiel comes to Dean again with Uriel, telling Dean they plan to destroy the town to protect the seal, and that he and Sam should vacate. Dean is outraged that they are even considering the plan, and tells them he's not going anywhere, and that he'll stop the seal from breaking himself. Castiel later reveals to Dean that their true orders were to follow Dean's commands, much to Dean's surprise. In the same conversation, Castiel admits to Dean that he has doubts about the orders of Heaven, and tells the older Winchester that he doesn't envy Dean's fate.

The next time Dean sees Castiel is when the angels come for Anna Milton. Despite Castiel being part of the team coming to take and kill Anna, Dean saves Cas from Alastair in Heaven and Hell. Castiel repays him by stopping Uriel.

In On The Head Of A Pin, Castiel recruits Dean to help them find out who is killing angels. They want Dean to torture Alastair for information. When Dean begs Castiel not to make him open that door, Castiel admits that he's been demoted, primarily due to his affection for Dean. Castiel tells Dean he wishes he didn't have to ask him to do this, but it is necessary. Castiel manages to talk Dean into doing the torture, but clearly regrets it. When Alastair overpowers Dean, Castiel comes to Dean's rescue. Castiel is also overpowered, but is saved by Sam.

Castiel stops by Dean's hospital room and talks to Sam a bit before investigating why the devil's trap broke. Castiel then talks to Dean. By the end of the conversation, Castiel has admitted that it was Dean who began the breaking of the seals, the fall of a righteous man in Hell being the first of the seals.

In The Monster at the End of This Book, Dean asks for Castiel's help for the threat of Lilith coming for Sam. When Castiel tells Dean he can't, Dean tells Castiel to never ask for help from him again. However, Castiel slyly goes into great detail about exactly why he can't help, giving Dean the knowledge necessary to stop Lilith.

Although Castiel finds out something and attempts to get this information to Dean, unfortunately Castiel is dragged back to heaven in The Rapture. When he returns, he tells Dean that he does not take orders from Dean. Dean is not sure how to deal with Castiel's new attitude. But he still asks for help when Sam is detoxing from demon blood. Castiel makes Dean swear himself to the service of heaven and makes him wait till they call him in When the Levee Breaks. In Lucifer Rising, Zachariah calls on Dean, and he later finds out that the angels don't intend to stop the breaking of the seals. Castiel is clearly conflicted about the revelation, and is unable to look Dean in the eye. Castiel refuses to allow Dean to see Sam, and traps Dean in the Beautiful Room. Castiel returns later when Dean tries to call Sam, notifying him that he's "outside his service range."

When Dean asks Castiel why he came, Castiel attempts to mend fences. Dean responds by punching the angel (though this hurts Dean's hand more than Castiel's face). When Dean demands to know why they would do this, Castiel tells Dean, "I see nothing but pain here! I see inside you – I see your guilt, your anger, confusion… in paradise, all is forgiven. You’ll be at peace. Even with Sam." Dean is shocked by this and tells Castiel to shove it. Dean asks Castiel what happened, and reminds him that he was going to help him before. Castiel asks what Dean would have him do. Dean tries to talk him into helping, but Castiel refuses, though it's plain he's anything but content with his decision.

Castiel ultimately decides to help the Winchesters, and comes back. He helps Dean escape by banishing away Zachariah, then tells Dean that Lilith is the final seal, and that they have to stop Sam from killing her. He transports them to Chuck Shurley's home to find the location of Sam and Lilith, but is attacked by Raphael, the archangel in charge of protecting Chuck. He transports Dean to stop Sam and makes his final stand against Raphael.