To combat the monstrous beings known as “Outsiders,” which invaded from the depths of outer space, the world’s strongest Hero joined forces with the Demon Lord. Yet, even the combined might of the Demon Lord, the Hero, and the World Alliance was not enough—they faced a devastating defeat.

In a desperate bid to rewrite history, the Hero uses a secret technique to send the Demon Lord back in time through reverse reincarnation. However, the Demon Lord’s new life begins in the body of a young boy, tormented by cruel aristocratic society and forced into slavery.

“How… How is a slave this powerful!?”
“Powerful? This is beyond that—he’s a monster!!!”

Armed with his overwhelming strength from his past life, the Demon Lord vows to rise again. This time, he will hone his power even further to ensure ultimate victory and reclaim his throne!