Jaheira did a Leeroy Jenkins the first time I triggered this fight and died on turn 2. I reloaded and it was annoying but because I was not prepared for the positioning (move off the stairs into the room ASAP even if it means dashing with an action) and devastating enemy AE spells (save spell slots and reactions for the stuff that can really wreck you). Had I done the fight a third time, it would have been cake. Unfortunately this puzzle combat bullshit is par for the course in a Larian game. I wish it was not.