Will he move on into human/animal magic? It'd be a shame to ignore the other half of biology, especially when you could also develop lewd spells. By the way, could magic make permanet changes? Since rampant growth is a thing, i assume it's possible.
If he really wants some serious fire power he could try splitting molecules like water into hydrogen and oxygen. Should be enough to create a big blast. Would probably make him the strongest mage on the continent
it certainly is a pain in the to write systems.. I haven't done it, but I can imagine it.. just to prompt all that endless roll of stat page, then keep updating it.. uuuuuhg.. hurts just thinking..