Naruto System in One Piece - Chapter 515

Ling Fei, the son of a fisherman in Sanxian Island, was accidentally involved in a mysterious continent–Arad, after learning that his celestial destiny was shallow and that he had no way to ascend.

Sword, there are unique adventurers here. Ling Fei, who has just arrived, has a mysterious mission and an ancient blood. The silent Grand Forest is roaring, the ancient ruins of the king are lamenting, and it is unknown what the legendary headless horseman is chasing.

On the ground, Ling Fei gets acquainted with his partners, takes risks, and becomes a legend!

- Description from novelbuddy

Living as a concubine’s daughter in her previous life, He Danggui got herself and her daughter tortured and killed by her family and Princess Zhou, while her husband, Lord Ning, allowed them to do so for a secret.

After reborn as a child, she swore to hold back her kindness to the villains. How did she survive in a family with various secrets and conspiracies? Who would be her final choice? The love of her previous life or a new lover who could offer her a happy and simple life?

Sharing the identities of doctor, political counsellor and princess, was she able to bring great changes both in Jianghu and the imperial family? With her intelligence and excellent medical skills, would she let them pay for what they did to her or live differently as a new one?

- Description from Novelupdates

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

Reiji Saeki, who lives in the north eastern countryside town, lost his life in an accident during summer vacation. ……But before he knew it, a mysterious ball of light hovered in front of his eyes in a world of whiteness. That ball of light was a magician from a parallel world, and is looking for a person qualified to inherit the magic they had created to prevent it from being lost. Reiji, who rode on that suggestion, now lives in the parallel world Elgin, with a new body and powerful magical power.