MTL - I Have a System of Orcs - ~ Chapter 3

In the tenth year after the new era, the world finally came to an end. Zhang Mu truefully waited for his death, but unexpectedly found that he had returned to ten years ago. With his memory about the future, he swore that he would change the calamitous history, saving the earth from being destroyed! Walking dead, zergs, evolvers, and various mutated animals… nothing can stop him! The first step is to retrieve his identity as an era merchant , then find all the treasures he can remember to enhance himself!

- Description from Novelupdates

Dexter a teenager that always gets bullied by others at school was involved in a incident which required him to get a chip in his brain.Thanks to the help of the chip he had become smarter than the average human, leading to lots of new inventions and discoveries, and gains the ability to move through dimensions but as always there is a down side as humans get invaded by aliens in search of him.

When traveling back to Japan's late Muromachi Era, how to survive becomes a significant challenge!Now, Harano must live well under this high-difficulty challenge!