Please recommend an ancient novel that mainly tells the story of the princess and the emperor.

The female protagonist was brought to the palace by the male protagonist's father to be adopted as an adopted daughter. The male protagonist loved the female protagonist very much and once had a person who was no less similar to the female protagonist as his concubine. At the age of 13, the female protagonist once saw the male protagonist and a woman having sex and put away her love for the male protagonist. The male and female leads were both outstanding in martial arts. Moreover, the female lead often went out to play in the palace and later became the leader of the martial arts world. After that, the male and female protagonists went to other countries together because of "black oil"(oil). On the way, for some reason, the female protagonist pretended to have amnesia, and the male protagonist called her his queen in order to make the female protagonist fall in love with him.
I remember the title of the book was something called the queen

Answer 1

I recommend "Special Spoiled Cute Concubine: The Loser Killer's First Class Concubine". The female protagonist of this ancient romance novel is a princess of a fallen country, and the male protagonist is the emperor. In the story, the female lead was an assassin. After she transmigrated to ancient times and became the princess of a fallen country, she met the beautiful emperor. The two of them doted on each other. The story was interwoven with the power struggle in the palace and the investigation of the case. It was very interesting. I hope you like this fairy's recommendation. Muah ~😗