After Saving the Beautiful and Miserable Male Protagonist, the Plot Started to Go Wrong

(Lightning avoidance: There is no such person as Shen Yu in the original work. From the beginning to the end, the heroine never takes another person's body, she is always herself.) Lin Yu was originally a young master of the demon clan. On the day of his transformation, he was plotted by his tribe. The dignified young master of the demon clan became a plaything trampled on by others. Finally, he fell into the devil's path and became the new demon god. Since then, the spiritual energy has dissipated, the evil spirit is rampant, the lives are in ruins, and the people are in dire straits. In order to save the world, Tiandao chose Mu Yungui to bind the rescue system, allowing her to return to before Lin Yu turned black, change the plot, and save Lin Yu. With the help of the system, Mu Yungui successfully rescued Lin Yu. Just when the system was complacent and thought the mission was stable. Things developed in a strange direction. Under Mu Yungui's deception, it assisted her in killing people, stealing spiritual treasures, and training ferocious beasts. Eventually, she became a witch that everyone wanted to beat up, and even ranked number one on the most wanted list... It started to feel trance, no, isn't it a rescue system? Why is its host either killing someone or on the way to kill someone? Isn't this right? "You are not Shen Yu." Mu Yungui: "I'm not Shen Yu in the first place." "No, you are not Mu Yungui!" In fact, it should have discovered the clues when she killed the first person without expression! "I am." "You're not!" "I am." "You are not Mu Yungui, who are you?" Mu Yungui blinked his eyes and smiled harmlessly: "I am Mu Yungui." When Mu Yungui's pupils turned red, the system was horrified. Help, Lord Tiandao, my host has turned black! ! ! !