Dean watches him leave his head bowed. He doesn't feel as good as he'd hoped, as he does when he imagined this scene, over and over. Usually he felt redeemed, like this had made things better - like somehow tearing Castiel down to shreds and teaching him a little fucking lesson in being a giant douchebag fixed everything. Cured the Leviathans, left Sam on his own, put everyone back the way they were.

Apparently, that isn't how the real world works. Because watching Cas practically stagger away just makes him hurt all over, makes him tired and sore like a bad hunt, makes his stomach hurt and his chest feel like someone took all his guts out. It enrages him, mostly, that Castiel's slouched back makes him hurt his much. He didn't do this to Sam, didn't do this to the world. He should be scot free.

No, instead he practically wants to break down into sobs, and there's Cas, all perfect human being. He lets his anger consume, lets his feet walk the three steps down the hall. He lets his hand yank on Castiel's shoulder, and lets his fist crack against the man's face.