Rather make it
+2/-1 until end of turn, multiple uses per turn, random quanta.
That way, he becomes stronger... but weaker at the same time? if you know what I mean. The likelihood of casting his ability 12 times, and hitting each of the 12 elements is pretty rare, unless you have only just played 1 nova. Ie. having 1 quanta of each element, then it is possible... But the creature will die after he attacks... So sort of like a buffable spark? Eg. Maximum buff is +24/-12... So a 24/-10 creature will attack and then die?
Don't know if I'm helping or making sense!