Rescuing the Humble and Paranoid Male Supporting Character

Many literary works feature a despicable, lurking figure, like a rat in a sewer, who grovels in the shadows, obsequiously infatuated with the protagonist, resorting to any means necessary. They covet the protagonist, inflicting immense psychological and even physical harm. The system's mission for Jiu Shu is to repay these villains in kind, punishing them and making them regret the harm they've caused the protagonist. The seasoned traitor Jiu Shu readily accepts the mission, only to infuriate the system. *Who's following you in the dark?