Poe created Montresor, in the book "The Cast of Amontillado" because she didn't want him to be captured. She also wanted to give us the point of view of a bad guy, and tell us that even 'bad guys' have a reason for them to try to kill a person (crime!)
Poe chose somebody like Montresor because it is a first-person account, and what he says becomes a symbol for why he did it. He had mixed feelings, and that is why the writer's point of view is extremely hideous.
hope this helps
