Toaru Majutsu no Index - Volume 18, Chapter 5: The Mercenary and the Knight’s Encounter and Clash. Another_Hero.

A classic villainess/heroine tale that puts a new twist on the genre. This Industrial Era fantasy tells the story of Nadia—a secret agent with a dry love life and an unhealthy addiction to visual novels—as she Transmigrates into the body of Vivian Moore, the villainess of the novel, from a family of business CEOs.All the destruction flags were raised, and Vivian was at the end of her rope. Her life was about to take a turn for the worst, but with Nadia behind the wheel, she seized Fate by the hairs of its head and yanked it into a sharp U-turn.No more weakness was allowed! If something wanted to get rid of her, she would stab it to death. If someone wanted to trample over her, she would shoot them into a beehive. And there was no stopping her because she had the strongest weapon a main character can have: the System!

Levi, a young man who spent over a thousand years in a cultivation world, awakens in a hospital only to discover that two years have passed on Earth. The world he left behind has completely changed—mysterious spiritual energy has appeared, transforming Earth into a cultivation world filled with monsters, undead cultivators, and mysterious places like floating islands.Though Levi is furious that the entity who transported him to the other world failed to stop time on Earth as promised, he must now face the new reality. In a world now filled with cultivators, interdimensional conflicts, and the presence of a cultivation leveling system, Levi struggles to adjust to his weakened human body while seeking to uncover what happened to his mysteriously missing family.

Li Yi once lived the dream of every pro gamer. He was at the top of his game with the best equipment, the highest stats, and everything a gamer could ever hope for. However, he soon realized that none of his ill-gotten gains for his to keep when he was branded Public Enemy Number One and killed in the biggest battle of the ages.

Now, he has the chance to turn back the clock and return to a time before his first mistake put him on the path of no return. This time, Li Yi will make different choices. With that, comes many interesting encounters — like saving a woman in distress then making love to her seven times in a row while her child slept in the next room. However, will he get back to what truly matters?

One thing is for sure, with the memories retained from his past, he will become King of this game.

- Description from Novelupdates

This story is set during the end of the Sui Dynasty, a time where multiple powers struggled for supremacy and power.