The series brilliantly creates a world similar to ours but with a unique parallel history in which events happened but with different starts or ends. In modern times, the cops takes white supremacists way more seriously than they do in our reality, which is why people are screaming about "wokeness." But it's far more complicated than that, because its masked cops ignore civil rights and can be fairly lawless, which - guess what?! - is not what we social justice types are after.
The complex morality is echoed in the complex plotting, with a bunch of dark characters in a very strange, dark, violent world and a story arc chockfull of mysteries.
The cast is first rate, most notably Jeremy Irons as a peculiar aristocrat and the phenomenal Regina King as the ultimate ass-kicker.
As for its relation to the graphic novel and movie, I read/watched them but it was years ago and honestly I don't remember much of anything about either one except they were both quite good. I may like this series better than either so far (based on the first 5 episodes), but I couldn't even hazard an opinion on the debate as to whether it is to the source material. As an entity of its own though, it is absolutely brilliant, and I highly recommend it.
