Buy this book. If you have any interest in Chaos Space Marines, go read this book.
The Blood Gorgons are a strange Chapter of Astartes. They hold that brotherhood is to be honored above all else. So much so that they exchange organs and blood among pairs of Marines, making them blood brothers of a sort. It's a very interesting concept and one that works very well, in my opinion.
Seriously, outside of ADB's take on the Night Lords, this has been the most enjoyable Chaos book I've read so far.
There is some Asian influence in here, unless I miss my mark, and the daemon mythology is also more than just the usual Bible copy & paste, it feels a little more considered and influence by other cultures.
The story focuses on one Marine but I'm so interested in learning more about them, I'm hoping the book did well enough to get us a sequel.
I don't want to reveal too much of the story, but the Gorgons have to overcome some internal conflict that could tear them apart. Where most Chapters would be consumed by such conflicts, the Gorgons go out of there way to remain true to themselves. Very enjoyable.
Nitpick
My one gripe, and this is probably the fault of the Black Library itself, is that everyone refers to the Blood Gorgons as Chaos Space Marines. They even call themselves that. It became a little obnoxious and more than a little intrusive. Whether or not a Marine is in service to Chaos, they are Marines. Do we need to add the Chaos in there at any opportunity?! Why can't they just be Marines? Astartes? We don't call every servant of the corpse-god Loyalist Space Marines, do we?! It just got a little bit silly after a while, especially since there are no loyalists in the book. Why make the distinction? If I were a renegade Chapter, I would just call myself a Marine.
Codex
I've not given you all my opinion of the new Chaos Space Marine Codex, that's coming later, but I wanted to share one thing about the book that I don't like that sort of follows my previous paragraph.
The idea that any Chapter that goes renegade must ALWAYS eventually fall to Chaos is stupid. The universe is so large that I can absolutely see Chapters simply choosing to disappear. Settling on a distant world and becoming lords of that place or traveling across the galaxy to continue to bring planets into compliance (honoring the original vision established by the Emperor before his death and the Heresy).
Everything in the Codex is corrupted. I'm using the Heldrake model but I can't stand it. My Marines are renegade, tired of paying taxes, killing and dying for a dead ruler. They'd not risk foolishly entering the Eye. But, the rules state they're all corrupted, all evil and just seconds away from turning into spawns. I can (and will) any Codex I want when I play them but it would be preferable to use the CSM book. I can't even imagine what Iron Warrior fans are thinking. I just don't like the shoe-horning.