Well, it is called Corrupted Kingdoms... what if instead of getting mc'd when the player defeats them, they instead get corrupted and are now on the player's team? No mc'ing anyone or anything, just corrupting them. Once corrupted, they just decide on their own to be on the player's team. For the ladies, it could be because of the player's D or some other lewd reasons; for the guys, it could be because of the player's high Charisma or Strength stat. And for some characters like Chloe, the corruption could just cause a split-personality.
This is the best I can think of with the least amount of reworking of things. About as close as I can come up with to just doing a search through all of the dialog (and the coding?) for "mc" and replacing it with "corrupted" / "corruption" / "corrupting" / etc.