How did the unreliable narrator affect the short story "The Cask of Amontillado"? Give examples.

Montresor is the unreliable narrator, meaning that we only experience the story through his subjective point of view. It can be said that everyone is the hero of his or her own story, and we understand that Montresor believes he is justified in what he has done in walling up Fortunato.
However, rather than persuade us to be on his side, Montresor ends up horrifying us at what he does. The result is that we feel pity and sympathy for Fortunato. For example, Montresor is vague about what crime Fortunato has committed to deserve his fate. Montresor merely tells us he has suffered a thousand injuries and an insult from Fortunato. Could he really have suffered a "thousand" injuries? What were these? What insult could have been so terrible it warranted inflicting a slow death on his enemy?
Montresor also unwittingly builds our sympathy for Fortunato by describing him in his Mardi Gras cap with bells, mentioning his difficulties breathing in the moldy catacombs, showing him drunk on a party night, and revealing that he is utterly unsuspecting that Montresor will do anything more to him than offer a taste of wine. He does not fight Montresor or suddenly admit to having done Montresor some terrible wrong. We as readers end up as bewildered as Fortunato is when he is walled up. All these details reinforce our sense that Fortunato is the innocent victim of a madman who has blown a tiny incident into a reason for murder.