Irony is a twist of a story line, usually with a moral, or a satiric context. It's a common literary device to create a situation and make a point in context. It's frequently based on the character of a subject, using the contrast between the known character and the story.
Examples of irony
A merchant was walking home from the market when he met a man on the road. They walked together as the merchant boasted of his successes and profits. Eventually the merchant realized he didn't know his new friend's name, and asked who he was. I am the Angel of Death, replied the man.
(Traditional folk tale)
A mother rabbit was speaking, endlessly it seemed, to a lioness about the achievements of her many children. She asked if the lioness had any children.
The lioness said. Yes, I have only one. But it's a lion.