Naruto System in One Piece - Chapter 507: Leming vs. Killer B

On that day, the fog blocked everything.

On that day, he became the captain of a ghost ship.

On that day, he stepped through the thick fog and confronted a completely subverted and fragmented world—the old order had vanished, strange phenomonoms dominated the endless seas beyond civilized society, and isolated island city-states and fleets of ships challenged the sea that had become the last ember of lights for the civilized world. All of this while the shadows of the old days were still stirring in the deep sea, waiting to to devour this world that was about to die.

But for the new captain of the ghost ship Vanished, there was only one question he had to consider first— Who knows how to drive this ship?!

- Description from Novelupdates

The unparalleled Demon King Ye Xuan, who was able to heal the death or the living alike and holder of the medicine Holy Scripture, was betrayed and killed by his fellow Demon Kings. But he reincarnated into the body of Ye Xuan, the prodigal son of the Ye family and vowed to himself that he would return to his peak and take back everything that belonged to him!

- Description from Novelupdates

The chief female forensic investigator, Ran Yan was secretly killed by her assistant. Unexpectedly, she was reborn in the years of the Tang dynasty. After experiencing a narrow escape, she fled from Jiangnan to Chang’an. Although, Chang’an was at the beginning of its flourishing period under the Li family’s Tang dynasty, various princes were vying for the throne by using all kinds of strategies. This was the dark days of the imperial court, where one needed to walk on a tightrope as one’s life was as powerless as an ant. The Xiao family controlled a large amount of wealth so inevitably they also became involved in the conflicts.

After arriving in Chang’an, she discovered many suspicious incidents: the original owner had unexplainable amnesia but his family was indifferent. She once again saw the orchid shaped clay inkstone, a valuable object that her mother has given her in modern times. Hence, could it be that she can time travel back? In order to survive in the Tang dynasty, she displayed her strong spirit and willpower by learning medicine from a doctor, pretended that she benefited from being sick on how to cure diseases, suffered hardship in earning money, manufactured penicillin, cured syphilis, and used her autopsy skill and experience to solve each and every murder mysteries.

- Description from Novelupdates

Lee Seongjin, the strongest hunter who defeated the demon king.
He possessed the body of the pig tr*sh Third Prince, the Holy Imperial Family’s shame.

But the members of this family… there’s something strange about them?

‘Overpowered’ Holy Emperor.
‘Regressor’ First Princess.
‘Player’ First Prince.

Lots of trouble and lots of words
The story of the Holy Emperor and his children.