MTL - One Useless Rebirth - Chapter 18 what happened?

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

Takebayashi Ryouma, a 39 years old man with hidden past, found himself in a strange white room. The gods tell him that he has died and that they are sending his soul to a different world, a world where magic exists. After living alone for 3 years, his gamer soul loses its common sense and starts along crazy routes.

The Revered Master, Yu Yan, known as the number one in the cultivation world, waited for sixteen thousand years, and finally took in a disciple. He taught her carefully, and took care of her diligently. He watched her as she slowly grew stronger as she comprehended the laws, and just as she was about to soar into prominence… she died!

Having brought up her younger siblings in troubled times and guiding her younger brother to the throne, Xia Wanyuan is the most legendary eldest princess in the history of the Xia Dynasty.When this eldest princess opens her eyes, she finds herself in a world a thousand years into the future. While she is still called "Princess", it's only a nasty jeer imparted on her as a mockery for her arrogant connections within the entertainment industry. So what if you were rich? In the end you've fallen to a status far lower than any beast!In response, Xia Wanyuan promises that a day would come when they will sincerely call her Princess. Everyone laughs at her, waiting to see the day when she'll be abandoned by the wealthy and affluent.Handsome yet aloof, President Jun Shiling is known only for his success in the corporate world with a demeanor cold enough to cut through ice. He has just one thing to say: Take the one hundred million divorce fee and leave quickly.Two years later, the eldest princess is a two-time winner of a prestigious acting award. The darling of the fashion world, she has become a style icon who is also proficient in the four classical arts. As an all-knowing professor in both literature and poetry, she is also a professor in two departments at the most renowned institute of higher learning. The Olympics? Gold medals are a dime a dozen when considering her skills in fencing and shooting. Her name is spread all over the world and she is filled with an unprecedented glory never bestowed upon any other.The CEO who wanted a divorce at the start refutes on television: "How dare anyone spread rumors about our divorce? My dearest wife, can we have another child?"