Wow, I've been having similar thoughts like this. Well, just a theory XD
Right!?!??! (≧∀≦)
Another theory i had b4 is because of iruma ring. It's something like solomon's. Idk it quite well but Solomon kinda rule over lots of demons and kinda become something similar like "demon king"?
Well they says that the ring chooses the next king WAHAHAHA. Anyone Im kinda accepting a little that Azz azz will be with clara. And iruma with the president
Is it just me? I was thinking what if the soul of the last demon king was iruma. But it was born and raised in earth. Iruma's parent might have formed a contract to sully before she was pregnant kekeke.. thats why sully brought iruma back to the underworld ,its his origin. Haha