The NPC sets out to defeat the demon king - Chapter 12

On a harsh rainy day, a high school student without any particular special skills, Usato Ken, got dragged into another world summoning with two others; a good-looking guy and a beautiful girl, both of whom he strangely started getting along with just today. As an especially talentless individual that didn’t stand out, he thought that the others would treat him like he was useless. However, they were unexpectedly kind.———“Maybe things will be fine?”Usato who found hope in another world thought that, but the reality was different. He had a certain magic talent hidden within him and he was forced to fall into hell under the name of “training”.

Until he became the lowest-ranked master, his lonely and luckless life never changed.Suddenly one day, a descendant injected him with a nanomachine, and the machine started ‘speaking’ to him.[I am the seventh generation Nanomachine manufactured by Sky Cooperation, and I am operating as a central nerve connected to your brain.]“What? What are you talking about?”This was beyond the boy’s knowledge, he turned pale.The Nanomachine linked to his cerebrum realized the User was not understanding a single word it said.“Who are you, and why are you doing this to me?”[“I am the seventh generation Nanomachine.]“Nano Machine?”[Yes, Nanomachine.]The boy’s face hardened.Mashin was the deity the Mashin Religion worshipped, along with the Sacred Fire.The religions’ Master communicated with Mashin.“Um, are you really Mashin?”The boy knelt down and asked with a trembling voice. At this, the Nanomachine attached to his cerebrum realized it had been misunderstood.

A martial art expert from the Song dynasty lives like a Phoenix that can live again in another body after death. This time, he happened to take over the body of a Japanese high schooler who is also a victim of bullying and has a bit complicated family circumstances.

- Description from Novelupdates

On that fateful day, a voice in the sky told everyone on Earth that the world they called home has just been part of some sort of simulation.