Counterattack of the Cannon Fodder Chambermaid - Chapter 600

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates

Shao Xuan joins a friend in his expedition to a recently discovered archaeological cave. After he picks up an ordinary looking stone he is teleported to a different world and wakes up in the body of a small orphan child. The world he is in now is still in its stone age with primitive tools made of stone and the ways of the people are savage. Savage isn’t the only thing special about the people though, because they have superhuman strength, jump higher than trees and punch stones. In short, they are able to cultivate their bodies. Despite all this, it is a real struggle to survive because of the scarcity of food. Together with Caesar, his pet wolf, he tries to survive in this cruel world.

- Description from novelupdates

I am Supreme