KO One: I’m the Demon Lord, and I’ve Retired!

A million years ago, he was the only human Demon Venerable in the Demon Realm.

Between the twelve space-times and the Demon Realm, he alone stood as an insurmountable wall.

For ten thousand years, he kept the heavens in check and ushered in the most glorious era in the universe.

Then he grew tired.

The Demon Venerable sealed away his true body, and his soul fell into the cycle of reincarnation. Over the next hundred thousand years, he bore countless names: overlord of the universe, master of the Demon-Slaying Island, Dark Night Lord... Every identity became a legend.

Until one day, he awoke from his slumber, opened a convenience store, worked from nine to nine, sold drinks, counted loose change, and settled into retirement.

But...

Why was the world starting to tremble?