One more thing I love about 12x19 is that it amplified that Cas’ arc is not just about Sam and Dean, even though it once again was about Cas doing everything to save them.
By now, Cas knows that he is welcome in the bunker and in the winchester’s lives. Dean has told him repeatedly that he is worried about him when he is gone. He has his own room and he knows he can always come back, even if Dean can be expected to be angry with him. (”I’m not angry. I’m worried.” and “We are fighting. We’re fighting for you.”)
Yet, he still thinks he has to protect the Winchesters at all costs, those costs including his relationship with them and his own live.
To know why one only has to look as far as these two quotes:
“I just keep failing again and again. When you were taken, I searched for months and I couldn’t find you. And I just wanted - I needed to come back here with a win for you and for myself.”
“I am not someone you should put your faith in.”
Cas lacks faith in himself. He has failed so many times now that he is desperate to prove to himself that his very existence is still warranted.
Cas has no problem with his faith in Dean and Sam and by now, I think he even knows what he didn’t at the start of the season, that they love him for himself, not for what he can do for them. The problem now is that he does not think he deserves that love. He has to prove that to himself - and to them.
Yes, Cas’ depression arc is still not over, but this time he at least knows that there are people who love him unconditionally, which makes this journey solely his own.
He has to find his own worth again to find his place in the world.
Which brings me to this conclusion: Thank you, Andrew Dabb (and Bobo Berrens and Meredith Glynn), for giving Cas a story arc that does not stand and fall with the Winchesters.