Mushoku Tensei - Volume 19 Chapter 2 — Borrowed Cat

Ye Qiu transmigrated to a world of barren wastelands. He obtained the 10,000 Fold Return System.

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

Freshman student Yang Dingtian possesses the Nine Yang Body, found only 1 in million. His Yang Fire is incomparably vigorous and thus, he cannot be near a female’s charms for his entire life. On the night of his 19th birthday, he decided to bid farewell to his virgin life. After stealing and tasting the forbidden fruit, he spontaneously combusted as the result!

In death he crossed over to another world; a world that held respect for Martial Power. His, originally, catastrophic Nine Yang Body was the Nine Yang Body that couldn’t be seen in a millennium! He was saved by a mysterious old man when he was at his last moments and the old man received him for a disciple, then betrothed his daughter to him. Thus, in this odd way, Yang Dingtian became the successor of the largest clan under Heaven, and became the number-one-beauty-under-heaven’s fiance.

- Description from Novelupdates

Sequel of Allison, taking place about 17 years after the original series.