Ezidemili, the priest of the lesser god Idemili, is one of Ezeulu's enemies. As a character, he provides an interesting contrast to Ezeulu. Though we suspect that Ezeulu really is headstrong and stubborn, Ezidemili's obvious desire to ruin Ezeulu's reputation makes us believe that he's being wronged and that there are no truths to Ezidemili's accusations that Ezeulu is power-hungry.
Winterbottom is also a foil to Ezeulu. Like Ezeulu, who follows only what Ulu tells him to do even if it makes him suffer, Winterbottom follows the orders of the British Administration, even when he realizes that they make no sense. These two characters can be contrasted by their adherence to duty.