I agree with
@Meduchi. For what it's worth. This would be an AWESOME shonen manga; I'd pick it up in a heartbeat. Dark themes that aren't just "let's have some rape now", an origin story that cements some nice points about the MC, and it's even specific enough and low enough in terms of power and location that you could easily expand from here. But horror? No, not at all. The skulls are nice, but faces sloughing off are kinda overdone. I'm deeply disturbed by body horror, and I didn't feel a twinge at this one.