Naruto System in One Piece - Chapter 521: Reversal of Form

struggle for dominance, where power rules above all.But you are no chosen hero. As the third son of a Viscount, you hold no influence—just another noble without purpose. Your knowledge of technology and strategy? Worthless here.Then, everything changes.The cards from your favorite strategy game—the very ones you built and mastered—are now real. No longer digital symbols, but an army you can summon at will. In this ruthless world, where the weak are crushed and the strong dictate fate, this power is your key to survival.You refuse to be a victim. Armed with an army beyond imagination, you will carve your own destiny. Not just to survive—but to conquer.“Soldiers, attack!”..........Note: If you have any questions or comments, feel free to share them!

The main character is reborn as a character from a game he played in his previous life. This character falls into ruin along with the villainess, spending the last of their years together. A man named Kururi Helan.

Du Fei was reborn, and in this difficult era of extreme shortage of supplies, he started his wonderful life of opening and hanging…

- Description from novelbuddy

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.