Monster Factory - Chapter 758: Go back or leave.

Frank, a mercenary known for his cold ruthlessness, decides it’s time to leave the bloody world of the underworld behind. But the underworld has no plans of letting him go. Relentless enemies from his violent past keep hunting him, and eventually, they succeed—Frank is killed.But fate has other plans. Instead of staying dead, he is mysteriously reincarnated into the body of a cop in a world filled with crime, corruption, and dark secrets. With the help of a strange, all-knowing system, Frank is given the chance to live again—this time, to prevent crime before it happens.

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

“Shit, is this really how I turn out?!”In the time of war he was known as the Body Flicker, Forbidden Magic Maker, and the Golden Blur.Arthur Vaelthorne.He had so many titles that it was unsurprising that the empire was the side that won the war, all because he had participated in it.A man that had the potential to become the strongest, rivaling the old powers, and the talent to back it up....Only ended up as a hidden boss in a popular game, meeting his end at the hands at one of his own students.A powerful hidden boss, unfortunately he had the fate of any other boss: Beaten by the protagonist.Now, with a second chance and the memories of one of the game's top players, he has a chance to rewrite his fate.

When he did not know her true identity, he treated her very badly, he disliked her too much, she was not elegant enough, she was in the way...Only later did he realize that the woman was his legal wife! He repented, tried to recover her feelings, but she was determined to divorce him.