I'm aiming for short daily snippets here as much as possible (family permitting) so here is the next bit.
All I have is one last chance
I won't turn my back on you
Castiel knows that Heaven was never going to be the same place that he left, he knows that he had only one opportunity to slip back in and amongst the ranks of the angels before someone as capable of freedom of thought slipped into the power vacuum first. He followed his instincts on this and a part of him is screaming out that they were completely wrong.
He should never have left Dean.
So he watches. He keeps an eye on the hunter even as he makes his way through the ranks of the angels and cuts out those who truly agreed with Michael's plan to bring paradise to the Earth. He watches Dean laugh and joke with the woman Lisa and her son. He watches as Dean has the life that his brother wanted for him and he tries to feel joy in that. Castiel came back to Heaven so that his presence would not upset what the man was trying to achieve with this old flame. He returned to Heaven so that Dean could have a life.
He has to wonder why watching Dean as he is now is so painful to him, especially when the angel knows that this is something that the hunter has always wanted a chance at. He knows that this should be good for the hunter, should be something that he needs and yet he cannot help but notice that Dean's laugh holds little joy and that his smile is thin and brittle. The angel knows a great deal about the man. He knows what Dean experienced in Hell and he knows what the hunter has done in his life and it makes him wonder if that makes the man suited to a life of normalcy and routine at all.
It makes him wonder if he should have stayed.
Regret is something that Castiel is not accustomed to, is not something that he should be able to feel and he knows that there is a possibility that his Father left the depth of emotion there to remind him of one of the great wonders of humanity. He suspects that it is simply that he fell too far and felt too much to truly forget how to feel.
The angel will not turn his back on his friend, however, no matter the way that they parted and the tensions of his time on Earth, he cannot abandon Dean entirely. He never would, even though the hunter thinks that he believes that. Castiel learnt a great deal about humanity from Dean, he learnt a great deal about himself too, and so he will be there if the hunter needs him. The angel will be there to attempt to soothe the hunter's nightmares, he will try to understand the way that Hell haunts the man and the need to be accepted and forgiven for everything done in that terrible place.
Castiel knows that this will likely affect his standing in Heaven, his bid for leadership now there is no one to fill that role, but he will not let his friend languish broken and defeated in a house that he cannot call home. The angel also knows that Dean will not welcome this, that the hunter will push him away and berate him, but that in the depths of his soul Dean will be glad that Castiel watches out for him, glad that he cares, and so the angel will do it.
Dean's misery there is in part, he believes, his fault. He knew that when he decided to leave Dean would not be happy about it but he felt it would be necessary. He honestly thought that the hunter could be happy in this life that Sam wanted the man to have. He deliberately ignored everything that he has ever known about Dean.
Castiel pulled Dean from Hell, he held the hunter's shattered and terrified soul in his hands, and he knit together the body eaten by decay. He knows the man more intimately than even brother or father ever could and he knows that he will never truly understand Dean's complexities, Dean's overwhelming humanity. Given that he will never be able to understand this aspect of his friend, he will never know how to truly fix him either.
Dean is a broken man, damaged by Hell and betrayals, and Castiel does not know how to make that right. He wishes that he did.
The best that he can do, he realises, is offer to help Dean. He can offer to stand by the hunter in the way that he should have done after Sam was locked in the pit and support him as he struggles away from the memories of Hell and the things that the man has been forced to do. Castiel can offer the unconditional love of one who will never recoil from knowing the events in the pit and the actions that Dean took even though he knows that love will never be returned with anything other than a grudging friendship.
Take my hand drag me down
If you fall then I will too
And I can't save what's left of you
