KO One: I Was a Demon Lord, but Now I'm a Teacher?

Luo Yu transmigrated into the world of KO One over a hundred thousand years ago. As a magic-powered ability user, he became the supreme ruler of the Demon Realm! The entire Demon Realm and the Twelve Spacetime Dimensions trembled before him! He was hailed as the most powerful Demon Lord in the history of both the Twelve Spacetime Dimensions and the Demon Realm! Under his rule, the Demon Realm and the Twelve Spacetime Dimensions enjoyed ten thousand years of peace!

But after ten thousand years, he grew tired of his position as supreme ruler of the Demon Realm. He left the Demon Realm and withdrew from both it and the Twelve Spacetime Dimensions.

Over a hundred thousand years later,

Luo Yu became a history teacher at KO One, teaching his students a lesson.

Just then, Black Dragon, seeking to become a demon, set his sights on KO One...

At the same time, the Demon Realm, ten thousand years later, began stirring once more, planning to conquer the Twelve Spacetime Dimensions...

As the Demon Realm descended...

A figure walked out of a classroom at Bale High School and stood before an army of a million demons-

At that moment,

The entire Demon Realm army fell to its knees.

This novel and its characters are entirely fictional. Any resemblance to actual people or events is purely coincidental. Do not imitate.