The female protagonist is the youngest daughter of the demon king. After three reincarnations of the male protagonist, they never stayed together. The male protagonist kills one of her close relatives in every life, making her the third demon king. In the third life, the heroine married the hero for various reasons. When she was baptized by thunder, the hero used his mortal body to protect her, but he disappeared into ashes... After searching for thousands of years, she finally learned that the hero was the son of the Heavenly King of the God Realm. She felt deceived and disappointed, fell in love with the hero and killed each other, but together they saved the common people...