>>280185485Well, the chapter after that one Takopi is having a crisis since he assumed Shizuka was completely evil, but that now he's confused on who the bad guy is. I think it's pretty clear that Happians occasionally encounter objectively evil forces terrorizing the inhabitants, and it seems like they have no problem getting rid of them if it means drastically improving the lives of the rest. They have to stay within the rules though, or they're exiled like what happened to Takopi right after. He was clearly moved by what happened to Marina, so he purposefully overstepped that boundary for the sake of making her happy.
Because of that, I also think that a fragment of that desire to help by killing remained after the memory wipe, which is why he didn't just reverse time again when Shizuka was attacked and why he bashed Marina so hard over her head. The same happened in the ending when everyone retained a bunch of vague memories from timelines that hadn't even occured yet, so it isn't a stretch to assume it at all.