Kuja, this is absolutely pointless. The description of the spell says " A dome of pure light." That's all. If a dome of pure light hits Magus, and his body responds to it as though it does Lightning damage, then an energy blade made of pure light will do the same. If a vampire is hit by sunlight, and his body responds to it like it's fire, then an ultraviolet lamp will do the same. The Luminaire spell and the Light Reaver are both damaging forms of energy constructed of pure light. They're the same thing, but different from a flashlight.