Have we ever thought why most of us are interested in the story we read? I can surely say that writing a story is a complicated process. The writer has to think of how the story must be told, what effect must it have on a reader, and what is the best way to present his ideas. To bring the reader's attention, literary elements, the techniques or kinds of writing, are used by authors. The proper use of those elements enables the author to keep us interested while reading a story. Literary elements, such as setting, point of view, and the included dialogue, are all relevant to short stories, establishing their plot, mood, and theme.
Point of view has a major impact on the story's comprehension and is one of the things the narrator has to consider. As we probably notice, story "The Cask of Amontillado" by Edgar Ellan Poe is told from a first point of view by Monstresor.
He is not a fully reliable narrator, we assume, although from his revealed thoughts, feelings, and intentions (his plans to kill his avenger Fortunato), we better understand his "nature" (of how crazy he was). Thus, we suppose that we should not take his words for "thousand injuries" as a justice for his revenge. Just as many other major and minor things, author intends us to see such by using first person narrative. Likewise, horror that the author creates partially contributes to choice of the narrator. Similarly, the vivid pictures of the catacombs add even more terror to the story. And being so closely related, there's another relevant element in literature.