I have an Apocalypse City - Chapter 436 - : Monk

The Principality of Atall lies between two great powers: the Kingdom of Allion to the west, and the Holy Dytiann Alliance to the east. Leo Attiel, the second-born prince, was sent to Allion as little more than a hostage, where he studied and trained in the military arts under a frontier general. And now, the times have reached a turning point.

Relations between Allion and Conscon Temple, a neutral land adjoining Atall, have worsened. Percy, sent from Atall as reinforcement; Camus, a warrior monk; and Kuon, a mercenary from a remote region, join forces to resist the looming threat of Allion’s army.

At the centre of the fighting, the three of them and Leo are about to have their fated encounter.

I have a foster father…

Um, that’s not the important part. I just want to say, why doesn’t he understand the differences between boys and girls in this world? He insists a pornographic picture is actually a diagram of acupuncture points. And also…why did he raise me as a boy for 15 years?! It’s impressive that he can write prescriptions, but I studied poisons.

But, why is he a Fang Hua Beast…

Legend says, that there is a great demon, who is the human kind’s public enemy. He is the galaxy federations’ nightmare as he wanted to conquer the whole universe. On the first day, he completely took out the human fleet, plunging them into disorder. On the second day, he declared that he will wipe out the whole federation. On the third day, he declared——that the hero who shot him in their previous battle must marry him, or else, he will destroy everything.

The galaxy federation president and the council members had a long meeting after that. They decided to dispatch a soldier, Wu Xing Yun, and marries him off to the arrogant demon. Wu Xing Yun was once a hero who fought for the nebula, and henceforth, he was tasked—— for the sake human race and the universe’s peace, to eliminate mistresses, settle his matters with the mother-in-law, and fix the man’s crooked ways.

Wu Xing Yun was very perplexed when he asked his commanding officer: “Sir, why did it have to be this way?”

Commanding Officer: “Soldier, bear in mind, that this mission of yours, is for the sake of the universe and mankind’s happiness. You must hold on to your husband, and fight other mistresses! Do you have the confidence to accomplish this task?”

Wu Xing Yun, stood straight, saluted, and instinctively replied: “Sir, yes sir! I will accomplish this task!”

- Description from Novelupdates

A 34-year-old NEET otaku, chased out from his house by his family, found that his life is reaching a dead end. He then recalled that his life could actually have been much better if he had made better choices in the past.