Why does the game drop to 20 FPS during large exorcism battles?

During massive battles, every time I released a powerful skill, the screen would freeze momentarily—a deadly stutter in combat. I tried locking the frequency in BIOS, but the system rebooted after ten minutes, proving this extreme approach was unfeasible. I used the GamePP BIOS Load-Line Voltage Guide to raise the voltage from 1.25V to 1.30V per HWiNFO and adjusted fan curves. Frame rates stabilized at 60-75 FPS per RTSS, and Cinebench R23 confirmed a 5% bandwidth increase, with temps at 50-56℃ per HWiNFO.