Infinite Bloodcore - Chapter 64: My Name Is Cang Xu

A con-man and policewoman that are legends of their respective professions suddenly die, then are reincarnated and return to the Tang Dynasty of ancient China as little kids.

Accepting their second chance and forced restart, they choose to use the modern knowledge and specific talents that they have in their previous lives in order to live comfortably in this new life.

- Description from Novelupdates

“Young man… if you could go back in time, what period would you like to be in?”

Thousands of years ago, a small planet collided with Earth and destroyed the world. In five days, ninety percent of humans had been wiped out, leaving behind the last ten percent to earnestly struggle on death’s door.

Jinyu was one of those people who survived. Due to a special heredity trait, he could understand beast language. After the apocalyptic disasters, Jinyu had been living for a month with the few small beast brothers that he’d subdued. Previously, Jinyu had thought that he would live like that until he died. Yet, inexplicably, one day he opened his eyes to find that he was in a monstrous, lawless world that was full of vitality and life.

Jinyu’s transmigration into the future let him skip over almost one hundred thousand years. In the year 106825, beasts rule the galaxies and ‘pure’ humans are extinct. As the one and only ‘pure’ human left in the entire universe, Jinyu braves this new chaotic world to find a place for himself and thus begins to work at Beast Store number 138.

- Description from Novelupdates

There are always four kinds of people in the traditional Mary Sue world. The Male Lead, the Mary Sue female lead, the woman who never wanted to see the female protagonist live a good life, and the infatuated man willing to destroy heaven and earth to get the female lead.