As I discussed in my guide, the Hero's Journey has very little to do with a conventional set of "morals", and more to do with a journey of the self, and/or circumstance. There's also the notion of a "heroic code" -- which again, doesn't have morality ascribed to it. Only in our modern ideas of "heroes" do we attach morality to the equation: but morality has truthfully very little to do with the notion of the hero.
That being said, I think that, dependent on how one views Griffith's actions he is both an inversion of the standard Hero's Journey, as well a character that follows it; he certainly follows some of the categories I discuss in the "Villain's Journey" section of this guide as well. Griffith also "looks" like the traditional "knight in shining armor" archetype, despite his later subversion of the trope. This makes him a good canidate to be the "mascot" for this guide.