This seems promising with some more combos added in. If you can do what I'm thinking, based off of Nox, is to put spells that your hero can learn into one spell, and cast it all at once maybe. For example,
Your Sorcorer has Firebolt, Chain Lightning and Nova. By putting those three into one spell using combos you could cast all three at once. By doing that and having a larger selection of spells to use, I forgot what it was but it had menus within menus for spells, to combine to make that one killer spell.