There are so many characters that are all interlinked, somehow. It probably doesn't help that most of the characters are hundreds, if not thousands, of years old. There are also a TON of different organizations, and divisions within those organizations, and titles of people and titles of people's relationships to others...It was very overwhelming to get all this information so quickly, and kind of difficult to keep track of all this throughout the story, especially when you're trying to recall things explained early in the book. It wasn't until I finished the book that I discovered there's a glossary at the end...whoops. Anyhow it probably is inconvenient to flip back and forth to it on my Kindle.
Characters - there are about a dozen of them that are important. Probably more. They are all related to related to each other somehow, too, either by bonding or by living together, or by nature of their positions. Things become even more tangled up in this book as everyone starts blood-bonding with others, or at very least sleeping with them.
POV - changes very often. A little too often, IMHO. Almost all the characters get to narrate at some point: Simone, Arianna, Tor, Anock, Antar, Theroes, Oberon, Desiree, Crian..and those are just the ones I can remember right now!
While I liked that this book is long, I do think it could have been broken down in to more manageable chunks. POV changes could have been delineated better and maybe having fewer narrators would have worked just as well, especially since I didn't think the different narrators were very insightful. You just get told things - people were suddenly in love and feeling things they never felt before. That gets boring after 2 characters go through it, but to have almost everyone I listed above, and some I'm forgetting to list, go through it? Yeah, repetitive much?
Granted, while all those were what made me not like the book so much - overall it's enjoyable. You get a different telling of how vampires are created, some magic, lots of feuding, and general lack of communication between all parties. Then you add in old jealousies and personal preservation (and selfishness) and things get really hectic.
I feel like I've invested so much time and brain power reading this book I should read the next one too...