Reading about the confirmed attributes and one thing struck me about spell AOE, what if the Wizard who manipulates the damage can mitigate its effects on his companions? One assumes that the Caster is in control of his creation, or else how can he shape and direct it, so why not have him proof his companions against these effects? Obviously there should be a price for this, as a matter of strategy and balance, perhaps a daily or per encounter ability is burned up in the casting of these wards.
Would this totally unbalance the game, and destroy the usefulness of various protection spells, or would the fact that it is only the allied Caster's spells that are warded against and it does not affect the enemies spellcasting one jot make it more palatable?
Well ladies and gentlemen, is this heretical thought crime that eliminates careful tactical play or careful preparation by wise players and blessed by He On Earth?