The Principle of a Philosopher by Eternal Fool 'Asley' - Chapter 448: The Roar of Their Bonds

The opening of Pandora's Box changed the world, giving rise to an age of superhumans and monsters. Yet mankind was not safe from its own hubris, and in the end, it destroyed itself. It's the end of the world, but Sonya Chernovna has been given a chance for a redo. With her memories of the world to come and her deep hatred of the society that had risen out of Pandora's Light, Sonya sets out to change the future.Even if it means being the most heinous villain that ever lived.--Chapters release on Monday-Friday with side stories sprinkled throughout.

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.

The little handsome son-in-law passed through a world as waste material and the husband of a wealthy family. But because of his lacking aptitude, the wealthy family had driven him out. So he worked hard and found a more powerful family’s thighs to hold onto. Soon enough, he became the strongest son-in-law and husband in history.

In this world, it was impossible to practice martial arts. It was futile so he might as well take advantage of his wife’s thighs and maintain a comfortable and leisure lifestyle.

He’ll train his wife to become the strongest and best person in the world.

“Whoever dares to provoke me, let my wife kill you!”

- Description from Novelupdates