Successfully complete the indicated Mercenary missions in Empire mode to unlock the corresponding male and female costumes. Complete the stages multiple times unlock all the pieces.

Costume	How to unlock
Hawk or Owl	"Shao Hua Bandits", "Ju Zhang Bandits", and "Hei Shan Bandits"
Imperial or Princess	"Guard Lady Cai Wenji", "Accompany Lady Cai Wenji" and "Defend Lady Cai Wenji"
Kung Fu or Summer	"Wu Tai Monk's Training", "Wu Tai Monk's Challenge" and "Wu Tai Final Trial"
Occult or Sage	"Stop Insurrection", "Suppress Insurrection" and "Crush Insurrection"
Tribal or Wildcat	"Tribal Encounter", "Tribal Invasion" and "Tribal War"
Water Dragon or Pirate	"Jin Fan Pirates", "Qian Tang Pirates" and "Bai Bo Pirates"