Tbh, I'm really bad at trying to grasp a yandere's mind. I'm just glad the princess isn't the MC or FL... If I find a yandere-centred manga I really have to let it pass as a no-read, personally, no matter how good the story is overall. That's also why I won't ever completely read or watch Mirai Nikki.
Anyway. I hope Momon won't truly lose his humanity before he finds true closure in this world. He didn't have a choice but to play himself as the absolute King of Nazareth, so I can't help but root for him to stay relevant just to juggle himself in between humanity & the undead's M.O. & I hope his minions won't turn against him someday for being human before (or siding with humans or other species for the sake of maintaining his humanity).