It Seems That I've Slipped Into a Different World. Also, My Gender Has Changed. - Chapter 45: It Arrived, the Wax-Sealed Letter

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.

Traveling through the world of Naruto, he is just a four-year-old boy who has no talent, no family, no blood, and no tailed beast.

Unexpectedly, after completing the Jain test, the system suddenly awakened.

Since then, he has drawn the glittering fruit, the shaking fruit, the dragon-killing magic crystal of fire, the magic eye of death, Geass, the blood of the ancestor giant, the eye of reincarnation, the eternal kaleidoscope writing wheel eye…

Also, Demon Sword Muramasa, Death Note, Longinus Spear, Godzilla, Zanpakutō*Kyoka Suizuki, Zanpakutō*River Blade, Natural Teeth…

- Description from novelbuddy

A young man with an extraordinary mind is off on an exciting adventure when he mysteriously wakes up in the body of a feeble slave-guy in a different, rich in quirks world.

The main character, a selfish jerk, would use extreme means to achieve his goals. However, he never allows his base instincts to overrule his sense of decency. He always pays back both good and bad deeds.

Will his (terrible/excellent) mentality help him make a fresh start? Will he get through misfortunes and hardships of the new world?

She was forced by her husband and his mistress to jump into the sea and commit suicide, only to be rescued and taken care of by the jerk's uncle for seven years.