I love your ideas here, and I'd love to do something with Michael! It could be interesting to have him and Paimon really going against each other this time — Peter's Evil-afflicted, and Paimon's going to be revved up on all the bad energy around the town and just going really volatile a lot. He's also going to probably be helping Chara kill a bunch of people,,,, but in general he could definitely be seen just fucking random stuff and people up around the city, so there'd probably be plenty of opportunity for Celestial Michael to see him being a bad demon!