This rating is really for all the books in this series up to this point, including this one. And I really struggled with how to rate it, because there are some aspects that deserve 5 stars (or more) and some that made me want to give it 1 star. In fact, I can't remember a time I've been so conflicted while reading a book. I'm going to start by talking about the positives, because they are VERY positive.
The world-building done in this series is wonderful. It is creative, detailed, and extensive, and it just gets better with each book in the series. In the first book, I wasn't at all sure where it was going, but as I kept reading, I found myself drawn further and further in, and I suspect most lovers of urban fantasy will find themselves in the same boat. I don't know that I can point to a single aspect of it that is completely original, but in its current configuration, the world feels unique. The concept of the "good" demon and "bad" angel is a classic metaphor for not judging a book by its cover. The elaborate descriptions of the various realms of hell, the clear verbal pictures that are painted of how each demon appears, and the complexity of the various clubs (Afterlife, Transfusion, Devil's Ring, etc.) and other unusual surroundings is colorful and clearly paints it all for the reader.
Almost the entire supporting cast throughout the series is phenomenal and well-developed. I can honestly say I am curious about what happens to every single member of Draven's family and most of his council, not to mention Keira's other friends, both supernatural and not. At the end of book 4, when we are given our first glimpse of the world through eyes other than Keira's, it gets even better. This continues on into book 5, and I found the alternate points of view just made the story better and more complete. I am eagerly awaiting the next book in the hopes that we will continue to get additional points of view.
Just to reiterate here before I move on to the negatives, the positives I've mentioned above are extremely positive. I really can't say enough good things about these aspects of the storyline. Now on to the negatives. And they are, unfortunately, just as bad as the positives are good.
While the story that is told is fantastic, the writing itself is amateurish and verbose. Add in the constant grammatical issues and simple misuse of words, and anyone who feels strongly about language is going to cringe repeatedly. It was so bad that I almost put the first book down before I even got halfway through, and generally, it takes a lot to make me just give up on something. I questioned whether or not the author had english as a second language at one point, because the types of mistakes are consistent enough to suggest that they are following the rules of grammar from a language other than english. I'm glad I stuck with it, but the language problems never go away throughout the first 5 books. A good editor would have gone a long way toward making this series even better. Hell, even a copyeditor would've made it much easier to read. There is also clearly a misunderstanding of the purpose and meaning of epilogue, since approximately 25-30% of the book happens post-denouement.
While the descriptions are wonderfully elaborate and clearly paint pictures for the reader, they are also often endless. At one point, I realized I had just thread three pages of description of a single room. Frankly, I just don't care that much what the room looks like, and I find it hard to imagine anyone else does, either. The way descriptive language is used reminds me of being in school and having teachers ask us to write descriptive paragraphs; I remember writing long drawn-out descriptions just to use as many adjectives as possible, and these books often feel that way. The author has yet to realize there is a time and place for that level of detail, but not every single thing in a novel needs to be described down to the inch. By the time I reached the third book, I found myself frequently skimming through pages just to get past the never-ending descriptions and back to the story.
I absolutely loathe the main character. In that way, this series is reminiscent of the Twilight series for me. I hated Bella, and hard as this is for me to believe, I hate Keira more. I find her annoying, stubborn, and not very bright. She also apparently has absolutely no sense of self worth or self respect. Every time she makes a decision that is clearly going to get her in trouble, I just rolled my eyes and hoped maybe this time she would die. Then she died, and even that didn't end the pain of reading from her point of view. I am absolutely baffled as to why all these amazing characters like her, since she seems even less than ordinary to me. Apparently her soul is pure, which is great, but that combined with great hair appears to be the only positive qualities she has. As an example, in book 4 she has the means to ask a question once each day when she is desperately in need of information and guidance. She takes advantage of this opportunity a total of three times. Really??? How effing stupid can you be? Even when she's given a way to learn, she can't be bothered because she's too busy panting over the latest unbelievably hot boy toy she's picked up.
Lastly, given the depth of development of the supporting cast, the villains are nothing. We know next to nothing about them, and they are essentially nameless and faceless right up until the final confrontation. The only time we get to know a "villain" is with Lucius, who turns out not be a villain at all. This holds true for basically all the "bad guys" in the books. Even Aurora is one-dimensional at best, despite appearing throughout all the books as a major nemesis to Keira (at least in Keira's mind). We have no information about the Triple Goddess until book 3 is almost done, and even then it isn't until Malphas kidnaps her and begins his ritual that we really learn what the whole point of that particular story was; we never actually learn anything more about Malphas himself, let alone the other women who represent aspects of the triple goddess.
So there you have it. Despite endless frustration and the constant urge to just give up and put the series down, I've stuck with it so far because the story is just that damn good. I would strongly urge the author to get an editor or at least a copyeditor and clean these books up, because I think they could be so much better with so little effort. I eagerly await the next one, even knowing I'll still be hating Keira, cursing the author for misuse of words and bad grammar, and wondering why on earth all these amazing characters give two flying shits about an annoying moron like the protagonist. Truly baffling...