Not every Transmigrator is the Protagonist

Zhu Yu was a young and careless man, living off of his monthly earnings as a Herbalist. However, he was shocked to realize that he had passed away in his sleep, and even more so when he was told that he was granted a second chance at life. But even then, nothing comes without a price. I have to help the Protagonists stay on the straight path? What? If they go astray, I should get rid of them and serve as a temporary replacement until another protagonist comes by? What?!