The Mysterious Art Museum - Chapter 3 (1) - The Mysterious Art Museum

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

An immortal cultivator is murdered by her master and finds herself reborn in the strange world of One Piece. She hardens her resolve to once more tread the path of cultivation, only to find it won't be as easy as she thought.

Upon meeting the girl who would become her adopted younger sister, the duke’s daughter Christina regained memories of her previous life. Through those memories, she learned that her new sister, Mishuli, was the heroine of a certain story. And though the story depicted a Christina who abused her sister, the real Christina turned into a siscon who spoiled Mishuli to no end.

I was a 28-year-old researcher in Japan, and before I knew it, I have been reincarnated in a fantasy world.

Furthermore, I had a half-spirit father and a spirit mother.

An aunt who is deeply attached to father, cousins who are problem children. Girls who cause awkward situations as in an otome.

Furthermore, in order to gain the affection of a love interest, a cousin even had a word battle with a king!

I am very busy helping humans as well as spirits!

And when I find people who are targeting my father,

「I’ll crush you.」

The cheat protagonist deters those who aim at her family. This is such a story.