Fantasy: the Most Powerful NPC System in History

What should I do if I travel to another world? What? Time travel? What are you afraid of? Just be reckless. Anyway, you are the protagonist, a person with great luck. What should I do if I travel to another world and find that I am not the protagonist? This, let's develop in a wretched manner first. What if there is a strongest NPC system when traveling through another world? What? Wave! Keep playing, keep dancing. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.