What Is the Feeling of Twilight and White Head?

She was decisive and merciless towards her enemies. She had never thought about what love was, but she was helpless against him. He is wise and brave to save his brother, but he is in love with her, who is sinister, cold and unaware of who she is. She is lively, cheerful and exquisite. He is cunning, unruly and unrestrained. What kind of bond will form between them?