I always assumed this manga / story was going to end up with him just being that village girls' chaperone, so I never let myself get invested much. I like these types of isekai stories, so long as the MC doesn't tie himself down to anyone else. An example that I can think of immediately is Arc from Skeleton Knight in another world. It was awesome when he was just going around from place to place, doing whatever he wanted as a giant holy knight. Yet, within a couple of chapters, he meets that elf girl and from that point forward basically starts living just for her, which I find frustrating. Sigh.
Anyway, I'm surprised this took such a dark turn--yet going by the cover from the novel that I've seen, I get the feeling it's still going togo the route I dislike.