What is the narrator point of view in Frank Miller’s Sin City the Hard Goodbye?

Sin City: The Hard Goodbye is a graphic novel, so its point of view is visual. Instead of being described, the action is shown, and it is shown in a gritty, noir-inspired style that's echoed in the main character's method of speech. The text of the novel is all from the point of view of Marv, the main character. The reader is privy to Marv's thoughts, as well as the dialogue that he participates in, and gets background on Marv and Sin City from Marv's point of view. Marv's viewpoint as a narrator is unreliable, though. Marv is mentally ill, and he is unsure himself at times whether the events of the story are really happening or whether he has rounded the bend into complete psychosis, experiencing a delusion as he rampages violently through the city.