Jerga Ijeiska

He was the King of Gairadite and commander of the Demon King Subjugation Battalion two thousand years ago.

Jerga was Kanon's teacher and the hero that preceded him. Due to the death of his wife and child at the hands of the Demon King of Tyranny Anos Voldigoad, Jerga held a deep grudge against him and demonkind. Even after Anos sacrificed himself to end the war, Jerga did not change. He knew the Demon King would reincarnate in the future, so he set up the Hero Academy to pass on his hatred to future generations.


(Source: Maou Gakuin Wiki)