In addition to the responses already given, two of my strongest impressions of the narrator are how incredibly intelligent he is and how imaginative he is. For one, the narrator's references to items like "'the Night's Plutonian shore'" (the Underworld, named for the god, Pluto/Hades) and a "distant Aidenn" (the Arabic word for Eden or Paradise) help us to understand how incredibly well-read this narrator is. Further, word choices like "craven" (coward), "nepenthe" (forgetfulness), and a "balm in Gilead" (a universal cure) confirm his education and superior vocabulary.
The narrator's imagination is also quite striking: the multiple histories he invents for this raven are varied and fascinating. Perhaps the raven is a wanderer come from the Underworld, or maybe his master simply uttered the one word he speaks again and again so that the bird repeats it, or perhaps the bird was sent by some angel to distract the narrator from his grief; maybe, on the other hand, the raven is a tempter sent from the devil -- he might be a thing of evil sent to tell the narrator whether he will meet his lost Lenore again in Heaven. Such a list could only come from the active imagination of a person with a good deal of creativity and intelligence.
Poe creates a narrator who is profoundly unbalanced, both through his physical and mental tiredness, but also because of the way he is consumed by grief for his former wife or lover, Lenore. Note how the poem begins by introducing the narrator and the activities he is engaged in:
Once upon a midnight dreary, while I pondered weak and weary,
Over many a quaint and curious volume of forgotten lore,
While I nodded, nearly napping...
Not only this, but the second stanza explains how he is obsessed with thinking about "the lost Lenore." Even before the raven has entered the room therefore, the reader knows that the narrator is physically and mentally exhausted, at the point of sleep, and grief-stricken. This is important because it produces an element of uncertainty in the events that happen in this poem. The reader is never sure whether what the narrator reports as happening is accurate or whether it is just a product of his own tiredness and sheer exhaustion, combined with his loss.
One of the most prominent features of Edgar Allan Poe's "The Raven" is the theme of self-torture that plagues the narrator. The man who is mourning his lost Lenore is prompted, by the raven, to continually ask questions despite the fact that he knows the answers before the raven verbally responds.
Because of this, the narrator seems not only relatable and accessible, but also evokes empathy or sympathy from the reader (depending on if the reader has experienced loss before). The narrator states in the fifth stanza:
And the only word there spoken was the whispered word, “Lenore!”
This I whispered, and an echo murmured back the word, “Lenore!”—
Merely this, and nothing more.
Although the narrator knows that his "lost Lenore" is long gone and deceased, he still feels emotion powerful enough to cause him to call her name into the darkness, as if she can respond. She does not respond.
In the same manner, he interrogates the raven who can only say "nevermore," knowing that the raven cannot answer his questions - much in the same way Lenore cannot answer his calls.
By allowing his emotions to cloud his reason, the narrator becomes an understandable character with whom the reader can relate. We have all felt desperation at some point, and have allowed our emotions to take control. Poe uses this fact to create tension and a relatable narrator.