Skill Creation in the Fantasy World - Chapter 138: Volume 2- The Guild Wars: Start of the War.

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

After transcending to a new world, Ye Xuan miraculously obtained the Swallowing System.

In all my life, I’ve only made two mistakes that I regret. The first was filling out my entrance exam application wrong, and the second was offending Zhong Yuan. If I had to use an idiom to describe the impact of my mistake, it would be simply, ‘Life is no better than death’. And if I had to use an idiom to describe Zhong Yuan’s offenses to me, it would be simply, ‘Too many crimes to record’. And yet, for as evil and wicked as he was, he attracted girls the way that flowers attracted bees and butterflies.

It happened that one day, for some reason, I taunted Zhong Yuan, “The King of Hell sent you to torture some more people, didn’t he?” Without a change in expression, he replied, “In order to torture fewer people, I decided to just choose one person to torture for the rest of my life.” I asked him, “What do you mean?” He smiled at me and answered, “If you don’t go to hell, who will?”

- Description from Novelupdates