What is the author's style in The Sandman Vol. 8: World's End by Neil Gaiman?

The novel is related from the first-person point of view, and is narrated by Brant Walker, a subjective but apparently trustworthy narrator. Toward the end of the graphic novel the reader becomes aware that the previous narration has been delivered by Brant to an unnamed bartender; the bartender comments that Brant perhaps dreamed or imagined the entire series of events, and Brant acknowledges this to be possible but does not accept it as a rational explanation.