These self-sacrificing "characters" come in on a pedestal. Jesus, Buddha, and Krishna are usually the center of the plot. The fact of who they are makes their sacrifices meaningful. The same cannot be said about the Magical Negro. The Magical Negro is expendable because he or she isn't anyone special. The audience is not expected to feel great sadness at a Magical Negro's passing, at least not of the prolonged sort. The audience is meant to be a little sad, maybe a little disturbed, but then quickly turn to see what the main character will next do, especially since the main character is usually more energized after a Magical Negro's death; the path is usually cleared in some way. It brings to mind the ritual sacrifice of animals in some West African cultures where it is believed that through the animal's sacrifice, the sacrificer is given energy.The Magical Negro is therefore a symbol of exploitation.
veejane has noticed that this racial stereotype seems to have made its way, unbidden by the original text, into the television adaptation of Ursula LeGuin's Earthsea novels, because of the producers' racist casting decisions. As if making Ged, the hero, White, weren't bad enough already.