In order to portray characters and also to describe the setting and the main idea of the story, E.A. Poe uses a great variety of lexical, syntactical, phonetic and graphic expressive means and stylistic devises. All of them highlight a horrible and at the same time a tragic atmosphere which is described in the story. 

Among lexical expressive means we can see:

-         Epithets  (scarlet horror, august taste, deep seclusion, voluptuous scene, delirious fancies, gaudy,  fantastic appearance, madman fashion) which are used to characterize the situation in the country and the gorgeous abbey);

-         Metaphors  ( the masquerade license of the night, the brazen lungs of the clock,  the impulse of despair,  the redness and the horror of the blood) shows the atmosphere of  terror in the story;

-         Similes (the Red Death had come like a thief in the night, it was observed that the giddiest grew pale, and the more aged and sedate passed their hands over their brows as if in confused revery or meditation, a light laughter at once pervaded the assembly; the musicians looked at each other and smiled as if at their own nervousness and folly) describes the image of the Red Death and the inner world of the secondary characters;

-         cases of personification (And the life of the ebony clock went out with that of the last of the gay – suggests that the clock was beating like a heart; once the last reveler died, it had no more reason to live; the pestilence raged most furiously abroad – personifying the pestilence as an angry  person makes it seem like it is full of hatred; the courtiers… bid defiance to contagion. The external world could take care of itself – shows how the wealthy have no feelings towards the poor and suffering); some examples of personification such as “Time”, “Beauty”, “Darkness”, “Decay”, “Death” have a symbolic meaning and catch reader’s attention;

-         periphrasis (the creation of the prince’s own eccentric, yet august taste) is aimed at revealing the beauty of the castle.

As for the syntactic expressive means and stylistic devices  there cases of  repetition, enumeration and asyndeton in the sentence: “There were buffoons, there were improvisatori, there ballet-dancers,  there were ballet-dancers, there were musicians, there was Beauty, there was wine” which stress the image of the castle.

We can see here numerous cases of irony:

The Prince builds a castle to thwart the Red Death. He surrounds the castle with a "lofty wall" and with "gates of iron." The guests "brought furnaces and massy hammers and welded the bolts. They resolved to leave no means of ingress no regress to the sudden despair or of frenzy within." The fortressed castle fails to keep Death out and ironically keeps the guests imprisoned after the Red Death's arrival.

The Prince's purpose is to let his guests forget about death, yet the construction of his Imperial suite, with its "sharp turns" and "novel effects" do little to comfort them. In addition, "the seventh apartment was closely shrouded in black velvet tapestries that hung all over the ceiling and down the wall...The panes here were scarlet - a deep color."  That seems a strange way to help guests forget about death, but not as strange as the ebony clock that rings ominously each hour, causing all to cease their merry revels.

Elsewhere, Poe also uses effectively phonetic device alliteration, as in this clause: “His broad brow, with all the features of the face, was besprinkled with the scarlet horror” (broad, brow, besprinkled).

A combination of these expressive means and stylistic devices makes the author’s style highly original and easily recognizable