These darned milktoothed toddlers and their anal magic, it'll be the death of them...
Edit: On a more serious note, it looks like monsters are starting to break free from static video game world logic and following survival of the fittest without the demon king? Or, after reading back, it seems any sufficiently powerful demon can modify the weaknesses of their subordinate demons at will, so it might be that without the demon king to rule over all the other demons, renegade individuals are now trying to form their own armies to stake a claim?