Something simple, yet effective at showing the tenuous line between good and bad that the Anti-Hero walks.

i understand that idea, yes, but what would best represent that my dear fellow?

Hrmmm... perhaps a scale, a common symbol of justice, stained with blood to convey a sense of justice without mercy?

Of course there is also always simple balance symbolism that you can go with, such as a big 'A-H' that is equally black and white.

There are a lot of other very deep meaning symbols and other stuff I can get into, but I suspect that it would be lost on many people.

or, maybe on that scale could be a heart and a bloody dagger, would that send the message? of course, the A and H could work too

How about a behind view of the silhouette of an anonymous figure in a torn, blood-stained cape?

i'm thinking a character with a broken halo, or black wings. the 'fallen angel' kinda vibe. i think that would get across the gray morality nicely.