I had this idea for a wizard who was kind of crazy and believed he was the king of a nation that doesn’t exist. He would see the rest of the party as his nobility and task them with enforcing laws he made up on the spot. In combat, he would use “control” type magic like paralysis and counterspells to lock down his enemies, pronounce guilty verdicts, and issue death sentences which his noble companions would carry out. I don’t know if the spell list in D&D would support this kind of gameplay, though.