City of Sin - Book 1, Chapter 73

The moment Kazuma arrived in the world of Jujutsu Kaisen, a cursed spirit knocked on his door, making him panic.Fortunately, he awakened the mission selection system.[Mission Option 1: Look into Gojo Satoru's eyes for ten seconds.Reward: Mangekyo Sharingan][Mission Option 2: Change Mei Mei's hairstyle to twin ponytails and have an in-depth communication with her~Reward: Tsukuyomi!]During the Shibuya Incident, Sukuna went crazy.Chibaku Tensei, Infinite Tsukuyomi, Susanoo...Yuji: “I thought that Gojo-sensei was already invincible. I didn't expect Kazuma to be even stronger than him.”Since he had arrived in this world, Kazuma vowed to make a happy ending.Gojo becoming Go/jo? That won't happen in his presence.Yuki, Nanami, Mai, Junpei...?He's going to save all of them.***This is just a translation. All credit goes to the original writers.Raw: 咒回：人生选择，开局万花筒！

He Chuan transmigrated to an alternate world where everyone could reincarnate.

In this world, all citizens who reached 18 years old could acquire a chance to temporarily reincarnate to another world.

They could reincarnate to various worlds such as an Eastern fantasy world, Xianxia world, Western fantasy world, an urban world with advanced martial arts, or even a sci-fi world of the future.

They would acquire a mission along with the ability required to survive in that particular world.

If they successfully completed the mission, they would become a permanent Reincarnator. They could then embark on the journey of being rich and successful.

If they failed the mission, they would become ordinary commoners. The gates to the new worlds would be forever closed to them.

He Chuan reincarnated to his first world.

[You reincarnated into a world of martial arts. You are an orphan and a loser. You awakened the Deduction System.]

He Chuan devoted himself to deducting various kinds of martial arts. He extracted the essence of each technique and merged them into a unique system.

In the end, he became the greatest legend in Jianghu.

[You acquired S rank evaluation. You may choose to keep the power you gained during this reincarnation and use it again in your future reincarnations.]

He Chuan chose to keep the Deduction System decisively.

He then reincarnated to his second world.

[You reincarnated to a fantasy world. You are talented and are the eldest son in the royal family.]

Sit back and enjoy as He Chuan breaks through the limits of the world and crushes the void.

Li Xuan traveled through the world of immortality and opened the apprentice system, and both apprentices and apprentices could be rewarded for upgrading.

【Ding! Accepting apprentice Qin Yue, reward you: Innate Divine Power]

【Ding! Accept the apprentice Zhao Tian, ​​reward you: call the wind and call the rain]

【Ding! Apprentice upgrade, reward you: space shuttle]

….

Li Xuan, who accepted a bunch of apprentices, evolved infinitely in seclusion.

Ten years later, the Devil Emperor invaded and wanted to sacrifice the whole world, but no one could stop it. The disciples watched the world fall into despair in pain.

At this time, Li Xuan appeared and slashed a sword against the Demon Emperor under the watchful eyes of the public.

Boom!

The sky fell apart, the invincible Demon Emperor fell on the spot, and the entire dark world was swept away by a sword.

The disciples were horrified. It turned out that the strongest person in the world was actually the master who had been in seclusion for ten years.

- Description from novelbuddy

“In order to survive the future great war, we must take drastic measures. We need to summon warriors and train them before time runs out.”Thus, millions of earthlings were reincarnated in an alien, medieval world governed by swords and magic to save its prophesied doom.Among those individuals, one's situation inexplicably deviated from the others.Thrust into a rotting house in a ghostly body, Adam found himself bound to a wailing baby. With a heavily damaged soul and the snarky remarks of a system, he began his years-long quest to recover his body.Armed with his mind, he'll educate the baby and slowly watch him turn into a good youth. However, he would have to make a choice: suffer as a ghost until he finds an alternative that might not exist, or possess his body and reincarnate.He was far from imagining how dangerous this world full of possibilities could be, prompting him to question everything he knew... Including himself and this world's intentionally blurred history.