The master of the brave is the demon king

The Demon King Richard is the strongest demon king in history, but he is also worried about it. Because he is too strong, no brave man can defeat him, and even no one wants to be brave later. He had no choice but to cultivate brave people to defeat himself. When he was 777 years old, an accident called him to another world, and the girl who called him called him brave as soon as he spoke