Hoo boy. I know a sandbox-ish game with a Sano and Shinpachi who would literally die with glee if you looked over it. The sandbox in question is imperturbatus, it's an AU Harry Potter thing which is basically just a taken form and a check-in for AC. Pretty laid back and slow-paced with idiots having fun with HP style magic, mostly slice-of-life for the time being if that catches your interest.

There's also a Yugi Mutou there, if that helps with Jonouchi as well!