Once a top-tier assassin, Bai Huo finds himself in a post-apocalyptic world invaded by otherworldly beings, where he becomes a mentor for saving lives. One day, he unexpectedly receives a mission from the highest authority, requesting his assistance in rescuing the superhero who safeguards humanity, known as the Sacred Lord. Why has the savior of the apocalypse suddenly started underperforming? Disguised as the assistant to the Sacred Lord, Bai Huo initiates a ruthlessly unconventional treatment plan, aiming to cure the Sacred Lord in unimaginable and harrowing ways.