That Thoughtspore looks great! Sit four of them in a corner with various attack spells, maybe throw Battle Fury or the new Power Strike card on one, then have the Forcemaster charge into the fray. Makes me wonder what kind of spawnpoint the Forcemaster will have.
I also like your idea of a living spell as a creature separate from the Thoughtspore, though I think you would have to make it so that casting the spell costs something. Perhaps don't give it channeling, and require a full action to cast the spell regardless of what it is, but make the spell cost half its normal mana cost?
