Regent Little Devil Concubine

She was originally the eldest daughter of the Demon Cult, Xin Ling, the daughter of the leader of the Demon Cult, Xin Yue; He is a dignified regent, ruthless and decisive, yet very popular and praised by the people; He met her unexpectedly and fell in love at first sight. Regardless of the opposition of the world, he decided to marry her. He never imagined that on their wedding night, she would stab his heart with a knife without any emotion. When he fell into her arms, still with a doting smile on his face, she could no longer hold on, vomiting blood, and stayed with him. Three years later, he was ecstatic to meet again, but she had lost her memory and married someone else. Can he get her back, and can they reunite and work together again?