My justification for it being balanced is that it seemed to be fair in that it stopped 2 or 3 spells for 6 quanta, with the chance to be killed first, which seems fair compared to destruction or creature control spells. Lowering the absorption rate (maybe to 25%/33%) could alter the balance a little.
I like the weakening thought thematically, though I was trying to make it still somewhat feasible to put spells in your own deck given the benefit to your poppets. Any thoughts on how to fix that?