Apocalypse Au
Hi! So this was a few years ago if I remember correctly, but from what I remember the fic was an alternate universe where Angels had come to Earth and essentially just caused havoc. In this fic, Castiel had been imprisoned and tortured most (if not all) of his life, but I think Sam found and rescued him? Castiel was half human and half angel and as a result his wings were always present. Sam called Dean to come help him heal Cas. Dean at the beginning hated Angels and I believe was hunting the ones destroying the Earth. Sam called Dean because he could speak their language and Sam couldn't. Through the process of healing Cas, Dean and Cas grew closer and eventually started a relationship. I think the fic was relatively long and probably on AO3 but I can't say for sure. I believe there was also a second part where Dean and Cas had met up with Gabriel and a few other Angels who were trying to help humanity. I think Claire was a kid and also half human and half angel in that one? Any help would be appreciated!