Medaka Kurokami from "Medaka Box" has what abnormality?

Explanation

Medaka Kurokami is a super-powered character in the manga series "Medaka Box". Her most notable ability is called "The End", which allows her to negate any ability or power, effectively rendering it useless. This includes both her own powers as well as those of others. The name itself suggests that if used against someone, it would result in their complete and absolute defeat.