Good Omens? Have a bit of a hankering for Reverse Omens, but I'm up for other stuff, too. I play Aziraphale, too.
Or if anyone still plays Johnlock, I'd be happy to play either side of that.
Or maybe some sort of original line in a magical universe? I have a rough idea about the brilliant but distant master wizard getting close to his promising apprentice. Or (very loosely inspired by Naomi Novik's "Uprooted") a master wizard with an apprentice whose style/abilities in magic are the polar opposite of his own. Brainstorming encouraged here.