Jerga

Jerga (full name Jerga Ijeiska) is a key antagonist in the anime adaptation of The Misfit of Demon King Academy, particularly prominent in the Hero Academy arc (roughly episodes 9–13 of Season 1).

He was a legendary human hero from 2,000 years ago—the King of Gairadite, commander of the forces opposing demons during the great war, and the mentor/teacher of the Hero Kanon. Driven by a deep, personal hatred for demons (stemming from the loss of his wife and daughter at demonic hands), Jerga refused to accept the peace that followed Anos Voldigoad's self-sacrifice. Even after the war ended, he harbored an unyielding grudge against Anos and all demonkind, believing true peace could only come from exterminating demons entirely.

To ensure his vendetta lived on, he established the Hero Academy and indoctrinated future generations with his anti-demon ideology. In the present day of the story, Jerga manifests as a powerful, conscious magic/spell known as <Jerga> (or Demon Judgment/Demon Conviction), essentially becoming an abstract, hate-fueled entity designed to eradicate demons. He influences events through the academy's "Jerga Kanon" selection class and serves as a major threat during the inter-academy conflict, clashing directly with Anos and others in a climactic battle.

In the anime, he's voiced by Akio Ōtsuka (Japanese) and appears as a determined, vengeful figure whose fanaticism highlights themes of lingering hatred and prejudice beyond the original war.