Chizome Akaguro (赤あか黒ぐろ血ち染ぞめAkaguro Chizome?), also known as Hero Killer: Stain (ヒーロー殺しステイン Hīrō Goroshi Sutein?)and formerly the vigilante Stendhal (スタンダールSutandāru?), is a villain and ex-vigilante that is notorious for having killed many pro heroes. He is the primary antagonist of the titular Vs. Hero Killer Arc. 

Chizome is currently under police custody and locked up in Tartarus.

He'll Be Here In Little Witch Academia/My Hero Academia Crossover Show.