The narrator is given a sense of power because he is telling the story six years after it happened. He has full information on the character of the invasion, complete analysis and understanding of the events, so he speaks with authority.
He is also an expert in the field with more knowledge than the average person.
"For one thing, the narrator is a scientist and a friend of an astronomer, Ogilvy: this gives him access to the world of astronomy when most of the news about the first projectile from Mars is not commonly talked about."
The first person narrator, who is never named, is also determined to survive. He has a greater understanding of the invaders, so he goes to great lengths to protect himself, even killing another man who will not be quiet, drawing the attention of the murderous aliens to the corpse while he slips away.
In the end, the narrator is a uniquely thinking individual. He has survived, along with others, he briefly loses his grip on reality, but regains his senses.
Because of his knowledge, his experience, and his understanding of the invaders, he remains suspicious and guarded at the prospect of another attack, even when the government soothes the fears of the people by explaining that the invaders seem to prefer Venus for their voracious needs.