Kyoukai Senjou no Horizon - Volume 7C, Chapter 76: Hurrier in the Circle

Cosplayer Liu Mang accidentally crosses through time and arrived at the Eastern Han Dynasty wearing Aries Gold Cloth. (Saint Seiya!) He arrived on top of the walls of XiaPi right when it was about to fall to Cao Cao.

“Don’t kill me bro; I’m not working for boss Cao!”

“Hey! You’re slashing the wrong person! Boss Lu’s underlings are there! Not me!”

He accidentally saved Lu Bu who was tied up by Song Xian. He accidentally became the son in law of Lu Bu. He accidentally changed the history of the Three Kingdoms period.

When aluminum casted Gold Cloths are worn by generals like Zhang Liao and Gao Shun during the Eastern Han Dynasty, glistering on their bodies… When the soldiers in the camps are sporting mechanical crossbows… When crossbreeding of rice plants appeared on Lu Bu’s territory…

Liu Mang knows that a world belonging to Lu is coming.

- Description from Novelupdates

After dying from betrayal, Thomas reincarnates as Jolthar Kaelzhar, the neglected son of a powerful clan, just after his brothers kill him. With Jolthar's memories and the blessing of Qalena, Thomas vows to rise from his lowly position and claim power in his new life.

Abandoned at birth in a humble stable, Shirone was raised by commoners—but he was anything but ordinary. Blessed with remarkable insight, he taught himself to read at a young age. A fateful visit to the city introduced him to the wonders of magic, igniting an unshakable dream of becoming a mage. Yet, beneath the city's dazzling facade lurked a ruthless social hierarchy, where power and privilege crushed those who dared to rise above their station. As Shirone uncovers the world's darkest secrets before even coming of age, one question remains—can he defy fate and claim his destiny as a mage in a world determined to keep him down?

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