Naoto nodded, placing the pencil down. She didn't meet their eyes as she did so and took a shaky breath.

"It is because of the coral," she told them, "at least that's the collective thought. By use of spells or abilities, energy is drained from the one using the spell or ability. It can easily be restored by touching the coral, but for an amount of time you feel the power you use drain you."

From the sound of her voice, she speaks from experience. Yu would probably remember what she looked like after the coral restoration battles. She could barely see - let alone walk - straight and a couple days later ended up with bit of a bug. Yukiko, on the other hand, hadn't been there and had only been told minor details. Neither of them really knew what happened down there.