Aren't They Old Enemies?

Xu Ningshuang lost her mother at the age of 13 and was expelled from the family. She changed her surname to Ren and became Ren Ningshuang. At the age of 13, he became the sword in His Majesty's hand, Yueying. At the age of 18, he went to war for his brother and became a general of Pingqing. Really standing under the light, the intrigues in the court and the fight for the throne? Then let's solve them one by one… Just, that's not right! Aren't she and him enemies? How did they become a couple? The heroine x is a little expert at fighting monsters and attacking people, and the hero has a double personality. (It's not a dual personality, it's just pretending.) These are two people who are good at pretending...