Who is Mbwao Mowa from A Planet Called Treason and what is their importance?

Mowa is the tall, not beautiful, but beautifully-voiced black woman who lives in the tops of the trees at Nkumai and holds ultimate poetical power in Nkumai. She is blessed with a beautiful voice and leads the morning song each morning with her gorgeous singing. Although she seems to be very kind and proper, one can see that she is deceiving everyone all the while. When Lanik is captured, she seems to be sad and supportive of him but one knows she is really glad he is captured. The ultimate deception of Mowa is that she is not even a black woman at all but a white bald man from Anderson, one of many Anderson people who have disguised themselves with magic energy to seem to be what they are not. Lanik stays with Mowa for some time in Nkumai.