Castiel's self-esteem is at an all-time low. He can take attacks on himself, but attacks on the people he cares about, the people he holds in high esteem, are unforgivable.

He disappears before Crowley can do anything to him, reappearing behind Crowley quickly as the shape of his wings begins to become visible.

He starts to glow, lighting up slowly. "You won't touch her again."