The Misfit of Demon King Academy: Volume 11 (Light Novel)

Equis, the self-proclaimed "will of the world," has been defeated, and the world has been born anew. But the stolen firedew still hasn't been found, leading Anos and his friends to theorize that there may be an entirely separate world outside of their own. Just as they begin their research they're attacked by a mysterious existence which seems to prove them right. And while their unknown assailants are extremely powerful—as much as the mightiest warriors of the Mythical Age—no one seems to have heard of them. Could these figures, all wearing matching emblems, truly be from the outer world? Find out in the Sacred Silverwater Sea arc!