I was asked to tell what his role is but i am unable to understand where he comes into play and what his role within the sotry is...
can anyone else make light of this?
Montresor interests Fortunato in the nonexistent Amontillado by telling him that he bought it at a "bargain" price. Fortunato does not have to sample Montresor's Amontillado to make sure it is genuine before buying some of it, or all of it, himself. The wine must have arrived very recently aboard a ship from Barcelona. People, including dealers, haven't heard about it yet because it is "the supreme madness of the carnival," and everybody is neglecting ordinary business, including Fortunato himself. That is why it is, supposedly, a bargain. Fortunato could easily find that ship on the waterfront and taste the wine on board. Montresor knows this. Therefore he tells Fortunato he is on his way to find this Luchesi. Montresor appears anxious to get an opinion on his nonexistent Amontillado immediately. This can only be because it is now available at a bargain price, but it won't remain a bargain once word gets around that it has arrived in port. Fortunato does not want Luchesi to hear about the wine or the bargain price, so he is forced to accompany Montresor to his palazzo in spite of his bad cold and in spite of being inadequately dressed for the cold, dank catacombs. He disparages Luchesi as a wine connoisseur because he wants Montresor to depend on himself as judge. Montresor knows Fortunato from experience and understands that his friendly enemy is already planning to taste the (nonexistent) wine and declare it to be ordinary Sherry. Even before they leave the street he prepares Montresor for disappointment by saying, "You have been imposed upon." This will not only eliminate Luchesi as a possible competitor, but it will eliminate Montresor too. Montresor would not have pretended to be in such a hurry to get an opinion on his purchase if he didn't want to make Fortunato think he intended to buy more. He has already bought and paid for his pipe of Amontillado and had it moved to his palazzo--so why should he be so anxious to verify its quality now? Only because he would buy more if he were sure it was genuine.
Montresor seems almost as irritated by Luchesi as he is with Fortunado. Like Forunado, Luchesi is another member of the high society that is beyond Montresor's reach. He brings his name into the mix because he has contempt for him as well.
Luchesi is important to the story! That was the major impetus Montressor used to lure Fortunato into the scheme. Luchesi was used as an affront to Fortunato's pride "And yet some fools would consider him as knowledgable as you." From that moment Fortunato was hooked as he could not back down from that challenge.
Luchresi never enters the story in the form of a character. He is simply someone whose name is used in order to get Fortunato's interest up enough to encourage him to jump at the chance to try the amontillado. Luchresi, like Fortunato, is another wine expert. Montresor threatens to take Luchresi to the coveted amontillado if Fortunato isn't interested.
Luchresi was only in one part of when Montresor just said that to get his revenge on Forunato. He is not really that much of important character in the story.