I wanted to like this. I really did. And it's hard to review because I don't usually listen to audiobooks so I'm not sure how much of my opinion is down to the fact that listening instead of reading didn't really suit me. 
 I didn't like Adelina. I realise she's an anti-hero at best, so that's the point, but I didn't dislike her in a fascinated, she's such a dark character, I want to know what she does next kind of way. I disliked her because she was whiny and often passive. And the constant describing of her actions and thoughts by means of "energy" and "alignments" got grating. I understand it was how the magic worked, but it seemed over the top, like once she knew about this power she has it took over her entire personality - what she had of one, anyone. She also took far too long to make a decision and stick with it - though that might have been an audiobook thing, I read at a much faster pace than the narration, so the whole book felt deceptively slow. As for her darkness - I wasn't entirely convinced. She comes across more out of control and weak-willed than anything else. 
 It felt like there was a lot of repetition - the same points being made over and over again throughout the book - and too much description without purpose. Not that it was bad description, but it kind of swamped the story in places. 
 The plot had promise. It was often unpredictable, and when the action got going it was fast-paced and exciting. A lot of the other characters were interesting (though some were severely under-developed) and the dynamics of the group were constantly shifting and uncertain. Teren was a suitably creepy bad guy and has a lot of potential, which I hope might come out in subsequent books. 
 The twist at the end came as a shock (which is good!) and definitely hit me in the feels department, but then the story dragged on afterwards - the epilogue was too long, drifting too far towards what's going to happen in the next book instead of wrapping up this one. 
 Overall, I'm intrigued to see where the story goes after the twist, so I will probably pick up the next book in paper format and see if I get on any better when reading instead of listening.