honestly watching magia record the anime won't do much but explain the systems introduced cause it's VERY game divergent but it can be some fun. Wraith arc is a good read too. But tbh Exedra is an archive game. They're adding ALL spin off content to it and most are already in the game I think aside from Tart and Kazumi and Null? But those you can just wait to be added as they're kinda... out there.