The Void's System - Chapter 3: Ten Minutes to Die

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates

He rose from hardship, but was felled by betrayal. From then on, one man, one gun; treads the path between Evernight and Daybreak to became a legend. No matter what was destined to be his fate, he intends to become the ruler who dictates.

The male lead is devoted, the female lead is passionate, childhood sweethearts, everyday family matters, the ordinary daily life of nurturing a wife.

In order to protect my two sisters-in-law, I was possessed by a Fox Demon. Since then, I've found that the way all women look at me has changed...