I think I might've recced you before for Jade (and apologies for repeating myself if so), but I'd love to see her or Anzu at thefarshore, where I play Davesprite and also Shun from Yu-Gi-Oh ARC-V! It's an urban fantasy game where characters come in as either new incarnations of gods or as shinki (memloss'd weapons of gods), and while there's a regain system for memories and stuff, the mods count up any bonus AC points, so there's no having to do maths. It's also really backtag-friendly because of the time ratio, and doesn't power nerf.

Alternately, for Anzu, there's a few YGO DM characters over at khuioduan, which is a fantasy exploration/worldbuilding game that opened last month. It only has a very simple bonus AC system (and not one that gates any plot stuff), and I've found it to be pretty chill and very backtag-friendly in the time I've been there.