From Soldier to Officer: A Game Addict’s Journey - Chapter 340 - : Joining the Recognaissance Company

Accompanied by all kinds of crisis and despair, was the arrival of mankind’s first significant superhero.

When Kim Seojin opened his eyes, he found himself three hundred years in the future.In the last three hundred years, humanity went through a lot of changes. Science had developed, cities became more modern, and space travel became a reality. But all of that came at a cost.The world had become a plaything of gods. Every year, humans were selected to represent their race in a devilish game, all for the entertainment of the gods.Kim Seojin was one of the thousand people selected in a timeline where he didn't belong.There was one more person. A Regressor burdened with the memories of countless failed timelines and the knowledge of the destruction to come, was also a part of the game…

Through a mysterious portal, Chen Jin arrived at this strange place – a post-apocalyptic world where civilization had been destroyed.

Consequently, he found –

A piece of metal scrap
A robot trash collector
A battleground
A city
A ton and more of gold
A copy of high-tech documents
A…
In short, Chen Jin found a planet.

- Description from Novelupdates

There was a Senior Brother and a Junior Sister. One of them was transmigrated to this world and had cheats while the other was the reincarnation of a Great Emperor.