Thread:Yoush/@comment-22439-20140403130504/@comment-4311395-20140501165012

Please consider it from the individual's perspective.

From Illias's (from monster girl quest) point of view, humanity is something which she created that isn't doing what she wants anymore. So she decided to get ride of it and start over with a newer, more obedient version.

From the Demon Lord's monsters and humans were both created by the chief god and forced to kill each other in order to keep both populations down. In some ways, this means that the chief god had them kill each other just for the sake of killing. For a succubus, which is a monster with a special conection to humans, seeing her fellow monsters and the humans she grows attached to kill each other is unacceptable.

If you look the soceity of each faction, members of the same species are able to coexist without trying to wipe themselves out because they are kin. This would naturally lead her to assume that if she turned the monsters and woemn into attractive, non-murderous monster girls and human men into incubi, then they would try to kill each other because men and women need each other to make children to carry on their genes.

In other words, the demon lord simply wants to stop the killing by having humans and monsters become reliant on each other to survive, causing them to make love and not war.