The Demon Monarch System - Chapter 548: Astarat’s War: Humans v. Terrors (I)

Xu Yangyi, an 18-year-old high school student, for the reason that his older twin sister eloped with her girlfriend on the wedding day, was forced to be the surrogate bride by his own father. As a result, he became the wife of the man who should have been his brother-in-law.“You’ve gotta look at me carefully. I’m a man.” Xu Yangyi glared at He Jingyan, who was still getting fresh with him though he already knew Xu Yangyi was indeed a man.“Man?” He Jingyan fiddled with Xu Yangyi’s face with his big hand and gave him a sly smile, “You look identical with your sister, so it doesn’t matter!”

Three Days of Happiness is a novel by Sugaru Miaki, also known as Fafoo. It’s a rewritten version of the story originally posted to 2ch.

The premise of the story revolves around a shop where one can sell away the remaining years of their life, and the consequences of doing so.

“I Say A Little Prayer” is a short related story which was posted along with the novel’s release. It spoils some things about the main story, but nothing major.

Bai Aoxue, the best mercenary in the 21st century, is accidentally sent back to the Chengxi Dynasty in Great Continent due to an explosion in her mission, and trapped in the first daughter of Prime Minister. After her rebirth, she is set up by her father to marry the 5th prince Jun Yeyan who wears a mask all day long.
In the face of bloodthirsty enemies, discord between brothers, collusion among courtiers and invasion of enemy state, can Bai and Jun resolve the crises? What will happen to their political marriage? How will the fierce battle for the throne end?
With many twists and turns, the book brings you to experience palace revolution, love and hatred thousands of years ago.

- Description from Novelupdates

Zhou Wenwen, who had traveled to a parallel world because of sudden death, thought that he could only live in such an ordinary life in this life, but the golden finger finally opened. He has a store where he can buy technological items and magic equipment to ensure his survival.

But the threat that followed made him realize that this place is not ordinary, because there are Transformers, Marvel, the Dark Portal from World of Warcraft, etc.

- Description from novelbuddy