This story is kinda like Slime Isekai... except without the charm, worldbuilding, plot development, interesting characters– basically everything that made Slime good, Re:Monster lacks. The premise sets itself up as a unorthodox take on isekai, but that's a lie; it's just another generic power fantasy that doesn't care about actually telling a good story.
To top it off, it reads less like a manga and more like a novel with pictures, which kinda defeats the whole purpose of it being a manga adaptation.
TL;DR: It's the same old power fantasy harem isekai. If you want an actually good isekai about becoming a monster, try "I'm a Spider, So What?"
This one isn't worth your time.