>>716119174 (OP)Even if you can get around the Lazarus Dilemma (the one from the image, I'm sure someone will post it), there's still the issue of monsters being an inherently parasitic species to humans, and a really shitty one at that, because they prevent heir hosts from procreating.
Drop a few monster girls into a city full of humans and, given a few generations, at least half of it will be monsters. The only reason humans still opted to breed with their uggo wives was because Ilias instilled fear and repulsion towards monsters into them.
Without that, it's only a matter of time before monsters are forced to create human farms just to keep their numbers up. And at that point, you just end up with a Black Alice/Monster World scenario.