Idle thought… a class (probably some sort of wizard) that starts ridiculously powerful, but that grows less so through XP.
Like, imagine something like a Boaz, First of the Magi in Joe Abercrombie’s First Law trilogy. Ancient, ridiculously powerful, but each time he uses his magic there’s a significant risk of it going completely out of control and draining an enormous amount of vitality & power from him, vitality/power that he does not get back through any normal means.
At the same time, he’s got this enormous life history, a network of temporal power, and no shortage of powerful enemies and old grudges working against him.
You could flavor it a few different ways: an ancient magus (like Boas), a lich or mummy, a forgotten deity, a pharaoh/god-king.
I think a class like that could be made interesting. But could it be made in such a way that it didn’t completely overshadow the rest of the players? Is DW even the right game for it?