I know we are all speaking about demon! Dean because it’s a biggie but i wanted to speak about Misha’s acting here. When Metatron discovers him in his chair he says this:
To save Dean Winchester. That was your goal, right? I mean, you draped yourself in the flag of heaven but ultimately it was all about saving one human, right? Well, guess what. He’s dead too.
(I can’t find a gif of his expression here but it was like heartbreaking)
Then we have Metatron trying to kill Cas too and: (x)
Look at his jaw. When you don’t want to cry you press your teeth like that. Cas is trying not to cry in front of Metatron. He knows he’s winning because he’s recording everything but he also know he has lost this battle. After everything he has done to save Dean all has gone wrong.
And now look at this one. They way his eyes look down. He’s not even looking at the blade because he doesn’t give a fuck anymore. Cas was an angel who found a new home in a human who is no longer alive. Look at Misha’s left eye and tell me that’s not a tear. They way his mouth opens. The blink. This is the moment Cas know his life is nonsense. What’s the meaning of winning if your prize is not there.
Correct me if I am wrong but I think Cas thought he would beat up Metatron and would return with Dean and Sam and spend the rest of his days with them. Like family. That was his dream. That was his Heaven. And now, he know it’s not possible. So, that’s the reason he says he wants to be an angel again.
Dean was Castiel’s reason to be alive and smile and now he’s gone Cas doesn’t want to be a human, doesn’t want to spend his life making things he thought would do with his best friend.
Thank you Misha for being such a great actor and understanding Castiel’s feelings so good. Thank you.