Talk:Kenkou Cross Q&A/@comment-213.119.32.191-20141029200128/@comment-25035274-20141029204509

It's actually answered in one of the books. The reason the Demon Lord's armies haven't swarmed the planet (according to the in-world author) is because they're too busy enjoying themselves. In point of fact, the only reason they even attacked Lescatie in the way they did in the first place (according to the words of Kenkou Cross in Real World Form; see Session 6: Question 2) is because Lescatie had become exceptionally violent towards monsters.

In other words, the Demon Lord, et. al., would be happy to let things go as they are now, with them having their territory and the humans having theirs, except humans keep on with the stabbing and killing and murdering. At least, that's how I interpret it.

EDIT: The information about the Demon Army's lack of advancement is covered in Monster Girl Encyclopedia World Guide I: Fallen Maidens, which isn't quite 'fully' on this site yet. The part regarding the monsters not advancing quickly is covered in some of the information that was just added by Unstaible child earlier today, if I recall correctly. I literally just read it an hour or two ago.