I think it would be interesting to have astral spells that effected the enemy rather than wizards. You could put attack reducing auras on the enemies, polymorph them into something with less health, and cut their attack's power or accuracy, and so on. I do realize that you couldn't see the opponent's hand to choose the spell that would be made weaker, so it would apply to a random spell. Mutations would simply change the school of a random spell, and if a spell was made to do less that 0, it would heal. These would work well with Wintertusk, where I am guessing enemies will use far more astral spells. Like in celestia, there should be an NPC that gives quests for extra training points that would be needed. Thanks for reading my ideas!