Xiaochen returns but now she is up against Mira, the main heroine of GOH. Mira was a fairly weak character for quite a while but the series turned this into an active plot point that was quite impressive. Her desire to get stronger became the complete focus of her character until she finally achieved such abilities. Right now Xiaochen would not stand a chance against her and just gets completely overwhelmed in speed, strength, and technique. Mira Yu win.
Xiaochen is a character who started out as a fairly unmemorable one but gradually became one of the best characters in the series. She’s certainly changed a lot over the years but her power level has never dropped off. The Shadow has a good laugh and knows how to be in the right place at the right time but he’s really out of luck here. Her angelic abilities would take him down for the count. Xiaochen wins.