Have you ever thought of working with DxD? Maybe something like getting the Annyhilation Maker longinus and see where it can lead you?
Personally, I think you could go with slimes you can use for lewd (like modifying the bodies of others and shit) or something like those we see in Eminence in the Darkness. Just an idea
Personally, I think you could go with slimes you can use for lewd (like modifying the bodies of others and shit) or something like those we see in Eminence in the Darkness. Just an idea