I got sucked so hard into this series that I ended up reading books two and three in an afternoon. I think that says something on its own. I gave up a whole day to this, rather than the hour or two I like to devote to reading.
It's funny, too, because the style of the series really annoys the heck out of me. I love the darkness of it -- and I don't mean that it's set in hell with demons and witches and whatever. The author really does deal with some incredibly dark issues, and that tends to fascinate me. Add into that the fact that the author is alarmingly good at making me laugh out loud at silly things.
I think the thing that gets me about things is how completely off-the-scale everything ends up being. I mean, the author sets her own scale and immediately broke it. And then broke it again. And then broke the broken break. And the time-spans involved! The author doesn't have anything against having someone be alive 50,000 years ago, or something happening 1,700 years ago, or whatever. It's unreal. I honestly wish she had taken a zero off of everything, just to make it a little more palatable.
Magic seems absolutely limitless; it really doesn't feel like there's any rules at all to Jaenelle's magic, like she's capable of absolutely anything.
The characters lack depth: the villains have nothing to redeem themselves, and there are hundreds if not thousands of people that fall into the category of totally, purely evil. The good guys are purely good, sometimes bumbling, often opinionated and full of knowing looks. I really think the only two characters that were fully developed were Jaenelle and Daemon, though by the end of book three I could add in Karla and Surreal.
And, and. Naming conventions. Really. Gah. Ugh. It's a truly amazing horde of hokey names: Saetan, Daemon, Lucivar, Cassandra, SaDiablo, Hayll, Hepsabah, Hekatah... the list goes on... and the rings of obedience? The hokey was nearly overpowering.
Yet, despite all that, I did enjoy this quite a bit. Your mileage may vary.