The only surviving member of the Yuchi Clan of the East isle commandery. The Yuchi clan was exterminated because the Youngflame clan wanted the [Windwing evasion] divine ability. When she was growing up her father had a dream of restoring his clan but sadly when he was escorting his pregnant sister Yuchi Snow and her husband Ji Yichuan to the Ji clan he sacrificed himself when Dong Seven and his followers wanted to rape his sister . After her fathers death her mother died shortly afterward of grief and Xiyue was left alone until she met her grandpa a king of Grand Xia. She left with him and later she met Ji Ning her cousin.
She is very secluded she has a lot of hatred for the people that killed her clan and her parents seen when she tortures Dong Seven with 10000 torture techniques and then tortured his soul for a month.