Magic's Return: I Can See The Spirits - Chapter 5 Vaan Astra Vesta.

Mark is a genius military weapon designer who was kidnapped by a mafia gang after refusing to work for them.
They forced him to design unique weapons for five years, until one day he successfully escaped only to get shot by his trusted comrades.
*Ding! You awakened a weapon system.
When he opened his eyes, he was in a different body and in a different world.
"You want to kill a wild boar without being detected? Forget about bow and arrow. Here, I present you this sniper rifle."
"You want to kill a horde of goblins from the sky? Forget about those flying carpets and brooms. Here, I present you the fighter jet."
"You want to kill a dragon? Forget about taking the help of the S-class adventure team. Here, I present you a nuclear bomb."
Join Mark Spencer/ Lu Zhen as he brings the whole world to its knees with the help of his weapon system.
***
Note: Author isn't born in an English-speaking nation and has no editor either. So, please be understanding if there are any grammatical errors.
**************
You can also support the Author through Patreon

https://www.patreon.com/snowstar

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.

Once through the pirates, Lu En became the son of Monkey d Dragon, a grandfather named Monkey d Karp, and an unreliable and neurotic younger brother named Luffy.

Fortunately, the ghost back system is activated!

The completion of the ghost back is 10%, and the training effect is increased by 100 times!

The completion of the ghost back is 20%, and the training effect is increased by 1000 times!

…

One day, Lu En, a ghost-backed master, appeared in front of Luffy who was shouting to go to sea, and made Luffy cry on the spot.

Luffy: “The pirates in the sea are all monsters like my brother? I don’t want to go out to sea!”

Garp: “For a long time, the two boys, Long and Luffy, with small arms and calves, I really doubt that they are not my sons and grandsons. Like Lu En, they are the grandsons of the old man!”

Warring States: “The strongest creature in the sea, land and air is Kaido? No, it’s Lu En!”

- Description from novelbuddy

An immortal cultivator is murdered by her master and finds herself reborn in the strange world of One Piece. She hardens her resolve to once more tread the path of cultivation, only to find it won't be as easy as she thought.