A gradebook would really make this game a lot more complete.
Couple a classcraft exportable (to LMS) gradebook to powers and you have a really cool system.
I would recommend replacing XP with a new point system. Let's call it "Karma".
When Karma reaches certain thresholds, new levels unlock (permanently, cannot be deducted).
Karma is spent in the gradebook where students can manipulate due dates and change late penalties (as an example) with Karma powers (rather than AP powers).
In this way, Karma becomes like a student credit score. Where credit is good behavior.
High Karma should be rewarded as a goal to work toward so that students don't just spend it when they have it. Create passive (buffs) that automatically alter gradebook submissions (like add 1%). or help in boss battles (like deal increased damage).