A New Snake In The Shinobi World - Chapter 388:

The world had changed when the System arrived, alongside the Cataclysm that filled the world with monsters. The technology was gone, replaced by classes and skills that allowed the people to fight back. When Devon ended up as a Blacksmith, a class that didn’t grant Intelligence, he had to face the reality, that his old career that he loved - mathematical sociologist - was over. Instead, he had ended up as yet another discarded member of the production class, overshadowed by the existence of the System Shops to the point of total marginalization. But, what if all he needed was to reapply his scientific thinking to the System...

Zhou Donghuang, a man from the Earth, is able to destroy any planet in the universe without lifting a finger. His supreme will can sweep across the vast cosmos in the blink of an eye. And his immortal spirit can depart from his body and wander around the universe!

In Kunlun Mountains lies a circular slate, which brought him back to one thousand years ago…

- Description from Novelupdates

He was the cold-blooded prince of the Jin country. Decisive and smart, he had looked down on the world with apathy and disdain.

When Zhou Shu woke up, he learned that he had become a Forging Apprentice at a workshop in the Forging Division of the Great Xia empire.