The reason for the name was simply the the level of such a spell, the reference to the sun goddess simply part of the story and a lending of power. Telling stories of the gods was one of the basic ways of casting magic after all.

"Fire...." Futo didn't like what they were doing. Fire wasn't the answer, this was a creature that no doubt was affiliated with such. She could tell already. They needed water, but they needed a lot of it. "Do not feed into her specialty! Bring forth water!"

She cancelled her spell card and instead switched to summoning water, as much as she could. Surrounding herself in it and causing pillars of water to rise from the ground.