I, Am a Living Yama, Empress Advises Me to Stay Calm - Chapter 89

Crossing into the world of Naruto, and acquiring the One Piece system, with all the powers of the world of One Piece, swordsmanship, devil fruit, domineering.

-Do you think that your fire is very powerful? I have the burning fruit.

-Do you think that your thunder is very powerful? I have a thundering fruit.

-Do you think that your otter is very powerful? I have the frozen fruit.

-Did you said you want to die? Don’t worry, I also have a nickname: Death Doctor.

- Description from Novelupdates

Her – a glutton without troubles or worries who crossed over and became a young fat chick with a deep vengefulness.

Him – a young master of the number one power; a two-faced man with elegance and charming, good looks; he is the chosen one of the former saint god and a man who will only bend his back for her alone.

This domineering crossover’s slogan is, ‘Don’t touch if it is this sister’s, put it there if it isn’t this sister’s!’

…watch how the Domineering Glutton and the Two-Faced Venerate Emperor create sparks as they meet and collide, stirring the whole Spirit Treasure Continent into turmoil, how they fall for each other and how they kill each other, how life and death severs love.

- Description from Novelupdates

The queen’s essential feature is this: [must be a woman or a feminine-looking man].

In the Tranquil Sun province of the empire, there exists an unremarkable lordship known as Xue Ying Territory! This is the home of the Dong Bo clan, the clan of our hero Xue Ying!

His father, a commoner turned noble; his mother, a noble who abandoned her clan for love, and his brother, an innocent toddler. But peace cannot last forever, Xue Ying’s peaceful life is shattered, and the only way to reclaim it is through power!

- Description from novelupdates