SMTV: Vengeance, Demi-fiend Boss Battle | i3 2120/4GB RAM/GT 1030

I've been bashing my head against this son of a bitch for the past 5 hours, and that's not counting my attempts before today's.
If it wasn't for the game's Innate Skills, I wouldn't have managed, and even then it took me a while to get the blessing of the RNGods.
Murakumo's poor critical hit rate didn't do me any favors. Only after swapping it with Freikugel I managed to win.
| - PC Specs - |
CPU: i3 2120, 2c/4t running at 3.1/3.2 GHz
RAM: 4GB (2x2 running on Single Channel because reasons)
GPU: Gigabyte's NVIDIA GeForce GT 1030 2GB GDDR5, Driver Version 555.85
OS: Windows 11 Version 22H2 x64