As a completely new subject for Materia, I would like to see the the ability to level up Materia. I'm not sure what form this would take -- whether simply fighting while having the materia equipped or something more specific.

This would do a few things:
  • Give players another task to do, yet another milestone to achieve.
  • Create a new market opportunity, for those people who wish to level up and sell "already leveled materia" (If materia can be removed from an item only be destroying the item, this creates as a side effect a continuing market for slotted items)
  • Creates the possibility for more unique customization and sense of achievement with regard to a character.

In order to place some limit on people simply purchasing "max level materia", I would suggest that removing a materia from an item reduces its level by 1/2, or perhaps the total xp of the materia by half.