(Blue Exorcist/ Ao no exorcist) There was a sickness. Not everyone showed signs of it immediately, but soon, 15% of Assiah was infected with it. The sick had abilities beyond the ordinary, and were all separated into groups. The G's. The F's. The E's. The D's. The C's. And the B's. The A's were more of a myth than actual knowledge. Most of them were wiped out. Most of them. (Bonrin fanfic. This contains graphic scenes and bad language, read at your own discretion.)