Chizome Akaguro, also known as Hero Killer: Stain and formerly the vigilante Stendhal, is a villain and ex-vigilante that is notorious for having killed many Pro Heroes. He is the primary antagonist in the titular Vs. Hero Killer Arc. Stain is a cold, unforgiving and merciless man with a sense of duty to cleanse society of false heroes. He believes that those who work as Heroes to collect income are unworthy of being called the name and only All Might is a true hero. Due to his strong ideology, he took it upon himself to become the Hero Killer: Stain to stain his own hands with blood to purge fake heroes and change the current society.