So there’s this thing i noticed watching older episodes. We all remember the times Cas and Dean almost killed each other, but then ended up not doing it, because something overcame them.
Do you see how Cas holds Dean’s arm in both pictures? It’s like a connection. Cas is telling Dean everything is going to be fine. And he doesn’t even use words. And Dean knows it. He knows they will be there for one another. And not even manipulative angels or the mark of cain could ever change that.