MTL - Mysterious World, I Have Special Understanding - Chapter 13 you found out

Fate is weird. Of all the people in the world, why would it select me to send to a different world?

And what is it trying to do? Put up a show by giving me a system? But oh well, what do I care.

The previous owner of this body was a cripple and looked down on, but now I can slap their faces with my system.

Young masters? Get out of my way!

Princes? Geniuses? Oh please. I have a system. That does not mean anything to me.

I know that I am not the greatest. But fate gave me a cheat system, and I am not wasting it.

I am going to do whatever it takes to conquer this world. Fate forced me to do this. It isn’t my fault if I cause some ruin on the way.

Before death Qin Tailong left two magic tools to his son, Qin Dong. In his father’s last words, Qin Dong realized his father had been murdered by Lord Wanpeng, who coveted one of the family magic tools—mystic chaos ring. Bearing the hatred in mind, Qin Dong swore to revenge against his foe. He escaped to the mortal realm temporarily, continued to strengthen his cultivation base and studied the secret hidden in the seals of the ring. While reveling the secret, he found five ladies were the key to the release the seals. Their romantic relationship with Qin Dong was established the moment he was born.

- Description from Novelupdates

The whole world is subjected to a highly dangerous standardised exam called the Global University Entrance Examination. Answering questions by putting their lives at stake, they would live if they passed the test. Every month the exam will undergo reformation while, occasionally, it is random.

- Description from Novelupdates

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