It is that "Christmas Carol" and "Sub Zero" attacks that result in a wipe. Especially the former, The "HATE" skill seems to add some status onto my characters which I have no idea what. My guess is that it makes them more susceptible to ice attacks? A Christmas Carol does 3k plus damage to my Bubba (think it almost instant kill) and Pumpkin has been spamming Firaga every turn. Maybe I need to farm a bit and upgrade their armor.

BTW, nice one. I was not expecting Phase 2 to be this crazy compared to Phase 1. A vast difference in craziness