I failed so badly at my first attempt (didn't even reach the last phase) that I wasn't sure I'd ever kill her, but I tried again today and it worked, though it was certainly not a clean kill. The fact that the tri-beams attack ("Stand still") inflicts you with the recovery debuff is very harsh for a melee build that wants to facetank as much as possible. Also blessed be the grace period and her timing for the memory games.

Current (and final) build: https://pobb.in/hTZQDoAgT_6d It's basically the same as the previous videos, I just switched the amulet's catalysts and added some resist catalysts on the amethyst ring that don't technically matter but heh, maybe it'll help if I want to upgrade some piece one day.