What Should I Do If My Partner Turns Evil?

After a car accident, Ji Qing opened his eyes again. What he saw was neither heaven nor hell, but a mission handed to him by the System: reform the target and max out their affection for you.

Ji Qing: And then?

System: Then find a way to get the person you've reformed to kill you, so you can leave this world.

Ji Qing: ??

After thinking for a moment,

Ji Qing: That hurts. I'm not doing it!

System: Every time you die, your soul becomes more complete. Once it reaches 100 percent, you can return to your original world. Want to reconsider?

Ji Qing: I know a hundred ways to get myself killed!

Lu Xingyuan: Hmph.

The mission seemed simple enough, but could someone explain to Ji Qing why the person he was supposed to reform ended up going dark in every world?!