Can't take this fear/concern with a modified person being a monster thing seriously because other than the ethical implications which we have to think ourselves almost nothing real has been shown to us.
It's "show, not tell"!
Maybe this isn't a serious manga or hasn't gotten to the serious part yet, so for now I think it will be better to treat it as a shonen battle harem manga with a bunch of tropes.
Yes, that would be better for our sanity. Just consume the entertainment, turn your brain off and...-