Demon Lord Apocalypse returned from the Nine Nether Purgatory, only to find that the cultivation that he used to slaughter the three realms was sealed in the body of a good-for-nothing young man in the human world. In order to regain his power, he was forced to disguise himself as the opponent's "portable grandpa", and endured the young man calling him master every day while using the demon master technique to give warmth to the handyman sister next door. Until the day of the Immortal Competition, the young man was forced to a dead end, and the seal in his body suddenly broke - the entire cultivation world slowly opened his scarlet eyes as he looked at the figure that once made the world tremble.
