I don't remember them mentioning it so correct me if they did, but I wonder if it's possible to cast innate magic at lower levels to "pull your punches" magically as it were? I.e., shoot acid missiles that won't knock a kid over from the blast and only leave mild burns, or since he has the water goddess' blessing, become a hot water super soaker? Sui's concept of restraint appears to be very bipolar right now (either go all out or not at all) so I wonder if it's possible to make this a teaching moment for him.