4. Harvey Dent

I believe in Harvey Dent. That was a campaign slogan that meant more than just running for District Attorney; it was the heart of The Dark Knight. Harvey Dent is more of a damsel than Rachel Dawes. He loved her, and she loves him, but her goal is to protect him. She introduced him to Bruce because of her belief in what Dent could do for Gotham and its people. He fought corrupt police; he went after organized crime; he went out and inspired Gotham. Bruce thinks he can stop being Batman, and can pass the responsibility of looking after Gotham to someone like Dent.

Just as Bruce sees what he sees, Joker sees it as well and that little bit of darkness there. With just one bad day, Joker can destroy that hope, and he cunningly got just what he wanted – to make Harvey like him and not Batman. From that point, Dent’s submission to his darkest side puts the reluctant hero in a despair that he doesn’t escape until his back is broken by Bane halfway through The Dark Knight Rises. While Gotham survived, that hope it had at the beginning of The Dark Knight is gone, and so is eventually Bruce.