I read most of the manga under a similar premise of “taking the challenge” and it is sad how little it effected me. The plot is just so incredibly shoe horned together. Just the baseline of tge show being “he used his healing to travel back in time” like what? The main character sucks and I don’t think you are supposed to sympathize with him, which was fine enough. But every choice in the narrative is just so laughable. It’s mostly edginess for the sake of edginess in my opinion.

And what tge fuck did I do to become your enemy??

Dedication. In a world where not doing things is vastly easier than doing things, the fact that they would do anything is frankly, a marvel.