The Bonechiller is now really hard. It took me several tries to beat her. I had success with putting the Insanity Core on Erica so they could use Misdirection, and repeatedly having Natalie cast Infernal Bloodlust on Erica. Then, I had Erica use Mana Burst, and spam Heart Blast on the summoned minions. I think I also just got really good RNG.