Rebirth in One Piece as Deputy Captain - Chapter 558

As long as the land is square, Yan Bicheng should divide the world into four parts.
The dark organization “Ruyimen” has abducted children for many years, trained them as assassin agents, and sent them to the families of various countries for use in order to collect a lot of secrets, and gradually extended their evil hands to the court.
Feng Xiaoya, the favored minister of the King of Yan, suffers from bone melting disease. She is unparalleled in her “sickness and beauty”. For some reason, she abandons the eleventh wife, Qiu Jiang, and puts her under house arrest in the mountains. Qiu Jiang, who has forgotten his past, fled alone on a stormy night. After several twists and turns, on the way back, he met Yi Fei, the third prince of Cheng who was in trouble in a foreign land.
One wants to regain memory, the other wants to regain the throne. The two people who are incompatible with each other walk side by side towards Cheng in a bloody storm… but they find that the Ruyi Gate, which has been entrenched in Chengjing for a hundred years like a poisonous snake, seems to have undergone an unknown shock… …
The situation of the Four Kingdoms is back, and there is only one goal – to eradicate the evil organization Ruyimen!
However, as Qiu Jiang’s memory slowly recovered, a unparalleled secret finally surfaced…
Mrs. Ruyi, who is it? There is another mystery behind Ji Ying’s death?
What is the purpose of this return journey after a narrow escape, and where does it go?

- Description from novelbuddy

In a galaxy far away, there is a kid without innate ability to practice internal techniques. So, in order to gain the respect of his father, he resolutely chooses to follow the more difficult and painful path of practicing external techniques. As the years go by, he grows up, but what really changes his life is a mysterious meteoric crystal stone – the Meteoric Tear. This stone fuses with the young man’s body unnoticed, and he seems to undergo drastic transformations as a result. After that, everything is changed. Eventually his father knows that the son for whom he hasn’t really shown a lot of consideration possesses astonishing abilities. And there’s a lot more to come.

She is a top-class spy, a poison specialist, but also a young and cute girl with a sinister temperament. In spite of her sweet and innocent appearance, she can complete any tasks without the slightest hesitation. One day because of an incomplete black magic, she was sent into the body of a girl who was deemed as a good-for-nothing. What kind of change will she bring to this continent?