The Fourth Mistress - Chapter 54 - Meeting You Again

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

When he woke up, Chen Xiao, a tech elite business genius, was reborn in a parallel world in 1999, another self standing at the gate of the college entrance examination.

This year……

OICQ was just born, and Goose Factory employees pretended to be girls and chatted with male netizens. Ma Yun was regarded as a liar and was forced to leave Yanjing to start a business in Suzhou and Hangzhou. Li Hong rented two rooms at the Yanjing Hotel and discussed the prototype of whiteness…

This year, Chen Xiao took the black technology guide of the future world, from social software to domestic systems, from domestic chips to artificial intelligence, from new biological energy to DNA remodeling to fight cancer; from quantum technology to anti-gravity engines…

He won the title of “Forbes” and dominated the global media. He suddenly found that he had accidentally changed the world.

- Description from novelbuddy

Summary Version 1:

The mysterious boy Ling Chen is saved by a little girl as he lay on the street dying. Years later, he strikes a deal to save this savior-turned sister and enters the virtual world. In a future Earth where advanced warfare has forced nations to settle issues virtually or else suffer the consequences, Ling Chen bursts into the scene and goes from unknown to legend. Yet all is not as it seems, for Ling Chen has a dark past, and there is a greater mystery at hand behind this virtual world.

Summary Version 2:

To save his terminally ill little sister, Ling Chen enters the newly released virtual game world and joins a small gaming studio comprising entirely of women. From now on walking upon his path towards the pinnacle. An ancient, evil item almost forgotten by history, the “Lunar Scourge” helps forge his unsurpassable legend, and causes him to unknowingly step upon a path that is destined to be punished by the heavens, the way of the shura.

When Su Jiu dies on her eighteenth birthday, she transmigrates into a novel about painful love and becomes an adorable four-year-old child.