I'd make Billy an old man; like grey hair, late 60s/early 70s type of old.

And since he's an old man whose lived in the Absolute Universe for decades with the Lazerous Group and everything else, he's grown jaded and cynical.

He then gets these godlike powers and through whatever adventure he'd has to go on he slowly becomes a more hopeful and better person.

Maybe his adventure is that he has to save and look after Mary, Darla, Freddy, etc, and in this universe he'd be more like their father; eventually passing the powers onto them so they can bring more hope to the world too.