So, after many attempts in the Bad Time Simulator (can't bring myself to do genocide), I finally beat sans. I'd like to share me beating his last attack here. It's not perfect,
Undertale Fight Simulator P1: Frisk - YouTube
Undertale Asriel Dreemurr Fight Pt1 - Physics Game by warrior101kdn
Steam Workshop::Undertale Boss Fight V 2.0.0
15 Really Creepy Video Game Boss Designs That Are Beyond Explanation | Page 7