Does the character change when in this setting.How.Why Does the character face problems in this setting that he would not face in other settings?
It depends on which character you are referring to. Montressor has an advantage in this setting. He is luring Fortunado to his death down in the wine seller. He knows the cellar and he has already supplied himself with all of the tools that he will need to wall up Fortunado alive and enact his revenge.
On the other hand, if you approach this question from the perspective of Fortunado, he is at a distinct disadvantage. He is sick to begin with and has a hard time making it down the stairs, but his desire to see if the wine is really what it is promised to be, a cask of rare amontillado, makes him struggle to continue on. The worst challenge he faces, however, that is based completely on the setting is the fact that when he is walled up alive no one can hear him scream. He has no way out, no hope of escape, and no hope of salvation. Therefore, for Fortunado, contrary to what his name implies, fortune was not to be found in this setting, only death.