In what ways does Montresor manipulate Fortunato? What weaknesses does Montresor exploit?

Even though we hear from our narrator, Montresor, regarding a lifetime of insults and humiliation that have been heaped upon him by the unfortunate Fortunato, we do not experience this behavior during their encounter in the story. What we see is the drunk Fortunato warmly greeting Montresor as an old friend. Because of his knowledge of Fortunato, Montresor is able to approach Fortunato as a friend without incurring any suspicion from Fortunato. Montresor then exploits this trust and his knowledge of Fortunato's character to murder him. Montresor plays upon Fortunato's knowledge of wine and his pride in being a wine connoisseur in order to entice him to follow him deeper and deeper into the catacombs beneath Montresor's home. He then uses Fortunato's disdain for another man, Luchesi, and his wine-tasting abilities to keep Fortunato walking with him deeper into the catacombs.
While walking, Montresor again exploits their friendship by expressing concern for Fortunato's health as his coughing becomes worse within the damp catacombs, though this is also a ruse. He knows Fortunato's personality and conviction will not allow him to turn back. Fortunato's implicit trust of Montresor is exploited to the point where the reader begins to question the reliability of the narrator and whether or not Fortunato deserves his truly unfortunate end.