Since there is shadow magic which I think is basically a spinoff of death but you change shape and gain power so thought make holy magic a spinoff of life but you change shape of something like a god. Holy magic would make you gain health each round unlike shadow magic which can hurt you. It would also make you have more healing spells for the time being. The catch? It cuts your defense in half.
Interesting idea dude i can see something like that go around. since we are making up elements i always thought of the wind element: they can inflict damage on all enemies and have high accuracy the trade on that is low damage like very low.