Primordial Soul's Rebirth - Chapter 21 - – Salamander.

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

Shi Jin was a desperate woman and just a pretty face in her past life. She was swapped at birth and brought up in a rich family, only to eventually die a horrible death.

Reincarnated into his college days. Zhou Yuwen knew the importance of a persona. In this life, Zhou Yuwen’s labels were aloof, mature, and exceptionally talented! “I’m quite traditional, I believe that if you’re in a relationship, you need to be responsible, so one must be extremely cautious about dating.” “Zhou Yuwen, let’s get remarried!” “Damn it! Are you poisoned or something? I haven’t even been married before!” “Stop talking nonsense! We were married in our last life!” “That was in the past life!” “Remarry!” “Go away! I have a girlfriend!” He fled, she chased! He couldn’t escape, even if he had wings!

Long Fei, a cross-timer and doujin, is an otaku who traveled to another world. In the original world, he was an otaku fan of Gundam and military science fiction.

He died in an accident and was reincarnated into another world. The Gundam works he had read before his death and the techniques in various military novels could be brought to another world.

How would he use the Gundam that Long Fei created? What waves can be caused in this different world?