Mira and Daewi are Mori’s two teammates so you can think of them as rivals to an extent. Both of them want to contribute to the team as much as possible. By the end of the series both of them have got tremendous power but I would give Daewi the edge in the end. His punches are just too powerful and Mira would have a tough time trying to get through the natural forces ability. Daewi wins.
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.