I'm not sure how balanced this is... I'm split. It doesn't take away all quanta, and it's pretty situational, but against AI5/6 it would be really powerful since those decks often go over 50 quanta quickly... it would make rainbow/chaos lord much easier... and it pretty much stops spell killing decks completely; although so do some shields... and even if it is balanced, I'm not sure how useful it would be overall.