Paula. I felt that way earlier in the season but now I actually think that she might survive it ... whether she comes out of it emotionally unscathed is another matter altogether.
Cliched but I feel like it's ultimately going to be up to her and her alone (not the people around her) who has to realise the path that she's going down ... will not end well, and at some point there's no turning back. I'm also with Marie in that I don't know if she can truly come back from it, if this is who she truly is now. Out of all the characters, I can't see where her story will go in season 6 because her evolution has been the most drastic/tragic etc. so that does make me nervous.