See also: Dean and Castiel
The older brother. A walking poster boy of gluttony and lust. Likes pie and his Chevy Impala.
Was rescued from Hell by Castiel because God had work for him. He doesn’t know exactly what this work is yet. Not the smarter brother, but more intelligent than he’s usually given credit for. Skilled mechanic.
Would do anything for Sam, including die for him.
In the story, falls in love or is in love with Castiel, depending on how I decide to do the plot.
Dean Winchester. So handsome he's mathematically impossible
Even now, in case John’s dying wish has worn thin after Dean paid the ultimate sacrifice for his brother’s life, Dean is still under pressure by a father figure, at this point the biggest daddy of them all, The Father, God. Like John, God sends Dean cryptic directives, in the form of Castiel dropping in and dropping bits and pieces of info in Dean’s lap, and expects Dean to take care of the situation.
The further Sam travels from the core family values, the more threatening it becomes to Dean, the more frightened he becomes, and the stronger his reaction. Sometimes he uses violence, whether physical or verbal aggression against Sam in order to bring him in line.
Sacrificing that much of his self didn’t leave Dean with much to sustain him in the absence of his family. The implications are that Dean will have a very difficult time sustaining himself outside of his family. He has invested so much of himself in them and cut of so much that wasn’t in their service that the loss of family means the loss of self. The two are so intertwined that the loss of one is the loss of the other. He has difficulty tolerating separations, whether emotional or physical.
To summarize,
1) Dean lost much more than just a mother with Mary’s murder, but lost all the things that make for a stable foundation in the development of the self.
2)John offered what Dean needed to reassert some semblance of that foundation, and Dean wholeheartedly accepted it. Because of the way John chose to cope with the destruction of his world, he demanded certain things from Dean, and Dean gave them willingly.
3)This allowed Dean to act on behalf of the family. He serves a strong role in preserving it against threats both from the outside and from within the family.
4)However, this comes at the cost of his self-identify. Dean’s identity is so intertwined with that of his family that the loss of family is equivalent to the loss of self.
5)This both prompts Dean to keep selling of parts of his humanity in the service of his family and leaves him terribly lost when separated from them.
It would be very difficult for Dean to stop doing all of the above. He’s been doing it since he was 4 years of age. Not only is it well-practiced and his personality is organized around it, but this mindset helped him and his family survive, and we don’t give up things that helped us survive easily. Instead, under stress, we tend to hold onto them tighter, more often becoming more like ourselves instead of exploring alternate ways of approaching our problems.
It seems, to Dean, that turning his back on what his father taught him means the loss of what he holds dear. “If I do everything my father tells me to, then everything will be all right.” And even if he learns that he needs to reject those things his father taught him, he faces additional hurdles. Turning away from his family’s core values means that Dean is giving up the very last pieces of himself, that all that he had sacrificed in the past hadn’t been necessary after all. And if it had been for nothing, then that leaves Dean with nothing.
And now for the spoilery stuff, post 4.16. Dean unlocked the first seal of the apocalypse by being “the righteous man who sheds blood in hell.” So now he’s got not only the guilt of failing his family (Sam’s turning more and more to the dark side, as evidenced by the increasing yellowness in his eyes) but the guilt of endangering the whole world. He thinks he can’t do it: he thinks it’s too big. And Sam thinks Dean isn’t strong enough, either.
Castiel seems torn: on the one hand, he doesn’t want to cause Dean any further pain (the line is something like “I would give anything not to ask you to do this” before Dean starts torturing Alastair, and that seems to be enough to change Dean’s mind), but on the other, the person who broke the first seal is also the only person who can stop the Apocalypse. If Dean doesn’t do it, no one else can. And Castiel loves the world too much to let it fall.