Naruto: The Mist Within - Chapter 110 - 109: New Beginnings

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.

Quinn Winter is a young man from another world. One day, he is suddenly chosen to become the new Demon King. But the Demon Kingdom is in big trouble – it's losing a terrible war against the human kingdom called Gran'le.To help his people, Quinn comes up with a risky plan. He will sneak into Gran'le and learn their secrets. But things don’t go as planned. A powerful noble sponsors him, and he ends up joining Heavenward Academy, the top school for training future heroes.At the Academy, there's a big challenge called the Selection. The best students become Paladins – magic knights who fight demons. Quinn doesn’t want to become a Paladin. He is a demon king! But now, he’s stuck in the Selection… and if he wins, he’ll become the very thing he’s supposed to destroy.He started the day badly. Now, things are getting even worse.

I never thought I had meaning to my life, but I guess I have a talent too.

「Get ready. The duel will begin soon.」

Eight years on battlefield and returning in triumph, only then to realize that the important army general is a woman?

Empress Dowager pass an imperial decree, bestowing An Wangye younger brother Xia Yujin as Nanping Junwang and to take the great general as the wife.

In front of the person that kill people like flies, iron mask ruthless of the wife.

Talent-less Jun Wang, in a world of ice and snow fraught with emotional and lake-like tears, request for help, “How to uphold the man principal?”

- Description from Novelupdates