The Immortal Venerables all fled to ascend, leaving the mortal world with piles of abandoned immortal sect junk causing trouble everywhere.
The layabout Su Xian was born with a special constitution. Cleaning up the immortals' messes made him stronger and earned him rewards.
The Heavenly Dao itself seized him and made him an Immortal Cleanup Agent, tasked with dealing with the messes left by the runaway immortals.
While others wielded flying swords to slay demons, he placated tree spirits, repaired thunder talismans, and managed mountain gods who skipped work.
His motto: be a slacker at work, cultivate immortality on the sly, and gather evidence along the way, then wait for Heaven to hold those hands-off Immortal Venerables accountable!