OT: I still don't think that there's an exact stat bonus that will be beneficial but balanced for ALL 12 elements.
This is true. But who said the bonus should be a stat bonus? I think there are lots of more creative stuff to create. Maybe those creatures should gain an "improved" skill, like a unique skill for each creature... Just my .50
I agree that a 'universal' stat buff is tricky.
My idea would be that perhaps any spells/perms/creatures (as in one specific type or just all) you cast from neighbouring elements cost 1 less? Not sure that's possible to do, but would be nice and perhaps lead to new duo/trio decks.
"hey Death, how's it going"
"cheers Fire, all good, was just wondering, do you think you could get me a discount on that firebolt, i really want to cast it?"
"sure, no probs mate"