After Shen Qingmo resigned from Systems 110, 119, 857, and 10086, they finally met the System they were destined to have: 120, their little shadow and cleanup crew.
With the 120 System on hand, Shen Qingmo felt that even if they accidentally ruined the original male and female leads again, they wouldn't be judged to have failed their mission.
In their spare time, Shen Qingmo most enjoyed hearing the protagonist declare, "Thirty years east of the river, thirty years west of the river. Don't bully a poor young man!" while wearing a furious expression. Then Shen Qingmo would secretly sabotage them, until the protagonist said, "...Don't bully a poor middle-aged man... Don't bully a poor old man..." and finally passed away, when the dead are beyond reproach. o(*≧▽≦)ツ
Sometimes, though, when the mood struck, they would give the protagonist a hand: "Watch him build his tower, watch him host his banquets, watch his tower collapse..." Whether the protagonist's tower actually fell was all up to fate.
Still, Shen Qingmo firmly believed that with the 120 System, their missions would never fail again. If anything went wrong, they could call 120 and bring the protagonist back from the dead, then keep teasing them. (A wicked smile)