User blog comment:Touchinos/Season 12 Finale Spoiler Discussion./@comment-69.129.120.213-20170415093633

Of course someone's going to die. I'm guessing Mary will almost certainly be the one to kill Ketch and in turn, somehow die herself. I know it's unlikely for Cas to die, however, he's had a couple of close calls this season already and has even said his good-byes basically twice. I think it would be dumb to kill him off considering the amount of times he's died already but who knows? I don't see Crowley getting killed because it seems the writers would want to make his arc come full circle, which would probably entail the Winchesters actually expressing some kind of affection for him, or he gets cured. This leaves me to this theory: While I'd hate to seem him go, I can see Lucifer finally dying. Most likely he would kill himself after his son is killed or something to that degree.

As far as cosmic consequences go, I've always believed that Death is still alive, just out of commission. Perhaps back in that magical coffin Bobby spoke of. After all, it seems a little weird that breaking a deal with a reaper would have bigger consequences than KILLING DEATH HIMSELF, which short of a few pouty lines from Billie, there didn't seem to be.