What challenges does Duncan face in The Faded Sun?

Duncan, because of his pivotal position in The Faded Sun, is one of Cherryh's most significant characters. He shares Niun's need to prove himself, but even more difficult, Duncan must accept the strictures of an alien society and a code of honor his own culture has long dismissed as outworn. He chooses to remain with the mri in Kutath, making it possible for men and mri to open a new relationship between their races, one that will allow them both to heal and mature.