@ lonewander1 Well, Fallen Maidens full name is Monster Girl Encyclopedia World Guide I: Fallen Maidens. Anyways, it consist about the author, the Wandering Scholar, fleeing from the Order after publicating his book, the MGE. He arrived to the recently-corrupted nation of Lescatia and seeks refuge in there, and later interviews it's new ruler, Druella, the fourth lilim daughter of the Demon Lord. In addition, he investigates the several recently-monsterized women from the nation, former heroines, each of them giving a brief acount of their background, history, etc. And all of them, I think, end up in love with one man: 'You', the reader or Elt (I know, it's confusing).
The nation of Lescatia, before it's fall, boasted the second most powerful military among all order-aligned states at that time. But more importantly, is the fact that it was the number one hero-producing nation in the world. For that reason, Lescatia was considered the light of hope for humanity and the Orde, and an extremely large threat to the monsters. But it easily fell in a blink of an eye due to Druella's invasion.
How? Because of the discontent amongst the people to begin with. The upper echelons of the Order, the nobles, ruled the nation at their convenience. Lescatia had a lot of slums with many of its residents suffering under heavy taxation, and many of the heroes who lived mostly in the central district, especially young heroes, didn't think highly of the government, the nobles, because they constantly ignored their will and tried to manipulate their lives. Which made more and more of them to side with Druella. That was the major reason for it's fall. Of course, if you read about the characters, then you will find out the other reasons.