Spoiler!
The masked guy is pretty obviously Kiyoung, but the reason he's doing this is because he wanted to inflict as much trauma and trouble on hyunsung since he knew he'd regress. (Suicide is prohibited because he needs Hyunsung to get more experience) His thoughts are basically "This guy has Regression powers (Mind's Eye), but he hasn't regressed yet, so there's really no point. Why don't I manipulate him until the point of regression so that my past self will be able to see he is a regressor and get absolutely carried". So yeah, this is all an elaborate setup by the first timeline guy. (Fun fact: Saintess won't be his lover in this life, but she actually was in the first Regression, because she got backstabbed and betrayed by those guys she killed)
The world is at chaos. It is neither fair nor sensible. It wrongs heroes, and breed scum. It is life with ugliness without a trace of beauty. The malice of the world, shall be sundered by the villain
