Ezeulu's downfall (situatonal irony)
The book’s conclusion is an instance of situational irony. Though we perhaps recognize the tragic nature of Ezeulu’s pride and anticipate that he will be humbled by the unfolding of events, we are nonetheless surprised by the swiftness and scope of his downfall at the end of the book.
The New Yam Feast that never happens (dramatic irony)
Because we are partially privy to Ezeulu’s scheming from an early stage, especially his increased decisiveness during his detention in Okperi, there is an element of dramatic irony that unfolds as we watch the people of Umuaro realize that Ezeulu will refuse to announce the date of the New Yam Feast due to his absence and failure to eat two of the sacred yams that mark the passing of the new moon. While the community is stunned, we are not so surprised.