Why does Nioh 2 FPS drop from 60 to 35 during heavy combat?

Facing hordes of Yokai was pure anxiety; my frame rate would plummet from 60 to 35, making parry timing impossible. I tried setting power limits to 'unlimited' in BIOS, but VRM temps hit 105℃ and the system shut down instantly. I then used the GamePP Power Plan Switcher to limit the max processor state to 99% and tuned the PL1 power wall to 80W. Cinebench R23 confirmed no more frequency jumps, with CPU temps stable at 78-84℃ per AIDA64 and VRM temps at 88-92℃ per AIDA64.