Some of them are little more realistic about it, like "well, Solomon's immortal" and they can just make MC that way too, thinking Satan, Lucifer, and Diavolo. Obviously some deny it hard, like Mammon, Belphie, Levi, and Asmo. I'm not so sure where Thirteen would fall, I'm thinking it could swing either way. Solomon would just be against unwilling/unknowing immortality for MC due to his own separation from humanity, but that's it's own post. It's got a lot of angst potential, I think, but also comedy.

Say, the gang having this little OH moment, and individually deciding to do something about it. Each of them have their own little scheme, some of them working together. Having looney toon shenanigans with a oblivious MC while accidentally foiling each other's plans. The Anti-Lucifer League and Party Duo accidentally screwing with each other's plans, leading to random scuffles MC has to deal with.