Who is Mik-api from Fools Crow and what is their importance?

Mik-api is a "many-faces-man" or healer to the Lone Eaters. Before White Man's Dog and Fast Horse go on the raid to steal Crow horses, they visit the healer. Mik-api prays for the two as they steam out the bad spirits in a sweat lodge. They face north, south, east and west as they smoke to the Above Ones, Below Ones and Underwater People. Mik-api gives White Man's Dog a small pouch that holds yellow pigment following the cleaning sweat that he uses to paint his body before entering the Crow camp. If the young man uses it exactly as directed he will gain both the strength and cunning to be successful in the raid. The two of them grow close and White Man's Dog becomes his apprentice.