The Simple Life of Killing Demons - Chapter 10Book 7: .1

She is the Crown Prince’s fiancee, but on the night of their wedding, an edict was made and she was given off to marry the crippled and paralyzed God of War.

She, a 21st century mercenary queen, had crossed over into a tragically betrayed body of a waste. Waste? She will show them what it means to be a waste! Betrayed? With the Ancient Manual in her hands, she will astonish all the despicable men and cheap women!

Wait! Didn’t everyone say that she was an evil woman which everyone feared? Why is his Third Highness, full of mystery and charisma, so interested in her?

- Description from Novelupdates

The traitor Gu Mang returned to his home kingdom again. Everyone rejoiced in his banishment. It was said the one who hated him most was his closest friend – the cold and stoic Young Master Mo.

A rumour: Young Master Mo prepared three hundred and sixty-five methods of torture to try on Gu Mang, enough to play with him for a year without repetition.

But what’s the truth then?

Well the truth is even more unspeakable–

Mo Xi’s identity: the most abstinent commander of the empire.

His relationship with the traitor Gu Mang: they’d slept together before.

- Description from Novelupdates

In a world ruled by ten royal families, Saruto was born into the Lewin family (the Dark family). He grew up carrying a promise he made to himself with his mother's last breath: to become the pride of the Lewin family (the Dark family). He is compelled to acquire power to help him achieve his goal. In his quest for power, he begins to uncover the origin of the Dark Power that suddenly appeared in his world without warning. He realizes that his family's history is deeper than he thought. How will he discover his family's history, and will he be able to fulfill his promise to his mother to become the pride of the Lewin family (the Dark family)?