Synopsis

When Demon Queen Echidna invades the human realm, everyone looks to the hero Leo Demonheart to save them. With his overwhelming power, he crushes her army and saves humanity—but instead of praise, he gets fear and hatred. The humans see his strength as a threat to their survival, so they banish him. Wandering alone, Leo eventually hears that Echidna is rebuilding her forces. He figures demons might actually want him around, so he heads to her castle and offers his help. Echidna shuts him down immediately. But her four generals are willing to work with him in secret, and that's all Leo needs. Under the disguise of a masked dark knight called Onyx, Leo starts fixing problems in the demon army—improving things around the castle bit by bit. But his real goal is to figure out why Echidna started the war in the first place.

Content compiled by AnimeList.moe from publicly available sources.

Genres