A Gothic Protagonist -emotionally isolated/alone
"You are rich, respected, admired, beloved; you are happy as I once was. You are a man to be missed. For me it is no matter." (Montresor 3)
Emotions Run High -defying their own common sense
"the cough's a mere nothing; it will not kill me. I shall not die of a cough" (Fortunado 3)
"Within the wall thus exposed by the displacing of the bones, we perceived a still interior crypt or recess...for no especial use..." (Poe 5) The secret room is the grave that Montresor makes for Fortunado.
Foreboding -ancient curses linger in the air
"Nemo me impune lacessit." (Montresor 4)
Montresor is emotionally isolated because he has no friends and no one to miss him.
Decay -formerly great family
"The Montresors," I replied "were a great and numerous family"(Montresor 3)
Fortunado is putting his own sickness, his cough, aside to continue down the vaults and to continue drinking wine. Fortunado is defying his own common sense by brushing his cough and saying he will be fine.
The Supernatural -unexplained manifestations
"Nemo me impune lacessit" means "No one attacks me without impunity". This is Montresor's coat of arms motto. This is an ancient motto for the family and it will be a curse for Fortunado.
Montresor is implying that his family was formerly great which indicated some form of decay.
"I discovered that the intoxication of Fortunado had in great measure worn off." Fortunado suddenly became sober after drinking all night.