Detective Conan: Death Note - Chapter 76: "Sorry, Ran Mouri."

In the current era, people are either normal or are with ‘special abilities’. Cases related to the latter are managed by the “National Anomaly Prevention and Control and Special Species Management Office”.
Qi Zheng Emperor Sheng Lingyuan was reawakened a thousand years later after he jumped off the fiery Red Lake. Xuan Ji, a newly transferred staff to the Reparations Division of the Deviant Control Office, finds himself having to clean up the mess of a revived tyrannical monarch. The two seemed to share something from the past, but unbeknownst to them, a big conspiracy is stirring right underneath their noses that could destroy the balance of the world.

- Description from Novelupdates

An orphan dies while saving a bus full of children. For saving countless lives, the Universe grants him the opportunity to transmigrate to another reality.

There he realizes his dreams of supporting his new family and opening a company that will shake the foundations of this new world. He will be known as the MasterChef of the gods, a superstar singer, the best Mangaka to exist, the best Director, the businessman of the millennium and many other adjectives.

I lived like any ordinary person when a stranger suddenly approached me, “You are… a hero.”

The eldest son of the assassin aristocrat Tuatha Dé.

The skill, experience, knowledge of the previous life, magic, all of which grows his power as an assassin.

Excellent assassins pass through. He was usually admired as the ideal lord, and behind it wielded a blade as an assassin aristocrat.