Who is Charles Mondial Vaughn the Fourth, Knight Commander of the M from Elijah of Buxton and what is their importance?

Charles Mondial Vaughn the Fourth, Knight Commander of the M, also known as "Massa Charles," is the owner of a carnival. He has purchased a slave boy whom he calls "MaWee," and employs him to assist Madame Sabbar in her slingshot act. The Preacher tries to make a deal with Massa Charles involving Elijah's "chunking" skills. When they cannot work out a deal, the Preacher puts a gun up Charles' nose and steals MaWee to take him to Buxton, where he will be free.