There are several main characters in Poe’s “The Masque of Red Death.”
Prince Prospero is the best realized: he’s the fullest character, presented in the most rounded detail.
The Masked Figure is less realistic, but may be more striking. He is the mysterious intruder who slips into the ball and leads Prospero on a confused and confusing chase.
The rest of the characters in the story can be treated as one collective character, like the chorus in a Greek tragedy. These are the “thousand friends” that Prospero invites. Given the way they act and react, it’s not fully clear if these characters are real, or if they are aspects of Prospero: dreams, hallucinations, fears, memories, etc.
Poe’s narrative voice is so strong that you could make a case for it being a character in its own right but a non-traditional one.
There are really only two main characters in Edgar Allan Poe’s short story The Masque of the Red Death. The first is Prince Prospero, the story’s protagonist, if that word can apply to a character completely lacking a moral compass. Poe’s story takes place during one of the smallpox epidemics that ravaged Europe due the Middle Ages, and the autocratic prince disappears with 1,000 of his friends and assorted sycophants into the security of his castle. As Poe’s unseen narrator observes in describing the merriment within the castle walls, its occupants oblivious to the suffering and death that is occurring outside those walls, “All of these and security were within. Without was the ‘Red Death’.”
Poe’s narrator wastes no time introducing the reader to the bleak environment in which this land’s population resides, describing the “pestilence” in the bleakest of terms. The plagues that devastated Europe condemned millions to the most horrific of deaths. Within Prospero’s fortress, however, all was good. As Poe writes, “the Prince Prospero was happy and dauntless and sagacious.” As the prince’s partying and jocularity continues, however, a mysterious figure is observed. Prospero has created an atmosphere of unrelenting debauchery, but he has failed, the reader will discover, to prevent the penetration into his domain of the plague to which those beyond his castle walls are succumbing. As the clock strikes midnight, some of the revelers become aware of the second of Poe’s main characters: “a masked figure which had arrested the attention of no single individual before,” and who exudes a sense of threatening menace, “a buzz, or murmur, expressive of disapprobation and surprise—then, finally, of terror, of horror.”
This second main character, then, is the Red Death, the disease itself. Poe describes this figure as follows:
“The figure was tall and gaunt, and shrouded from head to foot in the habiliments of the grave. The mask which concealed the visage was made so nearly to resemble the countenance of a stiffened corpse . . .”
The Masque of the Red Death, then, involves a fateful confrontation between the prince and the personification of a horrific death. All other characters, the revelers, the musicians, the fools, all serve a peripheral function in Poe’s story; they exist to emphasize the prince’s morally-degraded temperament. They are not, however, central to the story; only the prince and the Red Death serve that essential function.