If you want the deck to fit the theme you've given it, I'd swap out frogs for spirits, why not graboids if you want creatures that will gain attack/defense using certain quanta.
I like the forest spirit idea. The gabroid need 2 nova to cast and the idea is that you can cast any of these creatures with one nova and all of them with three. This might give you more consistency over the usual psnbow
I say no to Forest Spirits, and here's why:
Frogs deal constant 5 damage.
Spirits start with 1|1 and assuming you get a constant supply of
, it would take 5 turns before your damage output would equal that of your frog. Also, it would take 3 Supernovae to make this happen which seems to be against what you're looking for. Forest Spectres are also out of the question since they cost 3
. You might be able to get away with 1 Spirit and 2 Frogs, but certainly not replacing all 3.