The Monster Tamer - Chapter 12: Becoming a Warrior (2)

A boy from 21st century Earth, met an accident and later was reborn in Naruto’s Ninja World.
He is born in Uchiha Family and becomes the useless brother of Itachi Uchiha and Sasuke Uchiha…. Let’s see how he changed the Naruto world.

- Description from Novelupdates

In the year 2025, humans awakened with the ability to summon mighty beasts—capable of destroying terrains, breaking the laws of physics, and creating wonders limited only by one's imagination.But before these blessings came a curse.An alien face appeared from nowhere and threatened all life on the planet, leading to the greatest war in human history.In the aftermath, the human race and the alien race were forced into a shaky treaty that could be broken at any time.Years later, tests for summoning abilities began for the next generation. Those who awakened low-grade summoning would be thrown to the gutters, while those who awakened higher got to join great factions after graduating from the academy.Kairos Veyl, the blank, calculating student, pulled his hand from the massive crystal pillar and stared at the large beast before him.“This kid—he just got a LEGENDARY SUMMON.”A legendary summon? The greatest class of summoning. However, with this class came a risk one would have never guessed.

An ultimate warrior, the one and only Alchemy Emperor, Ling Han, died in his quest to achieve godhood. Ten thousands years later, he, with the ‘Invincible Heaven Scroll’, was reborn in the body of a young man with the same name. From then on, winds and clouds moved as he set himself against the uncountable geniuses of this new era. His path of becoming a legend has begun once more. Of all eras underneath the heavens, I am the strongest!

- Description from Novelupdates

Despite being the ruler of a nation, nobody was willing to marry the vicious man with a bloodlust.