There were many problems I had with this book. First off, this book's premise was intriguing - I mean, come on, badass heroine? Yes please. 
 This is set in a magical world where there are people called Ruined who has powers. Though I'm not too keen on how you can tell if all their powers are the same or if they are different. If she made it clear, then maybe I just missed it. I'm not too sure. 
 The world building in this book was definitely lacking. I can't really tell how these places are aside from there's a castle, forest...etc. I wish I would know more about these countries in this world and a bit of their history. All I know so far is that there's Em coming to save her sister and get revenge. However, (view spoiler)[ there's been no indication on why Cas's father wanted to kill off the Ruined. (hide spoiler)] 
 That aside, spoilers ahead! 
 (view spoiler)[ 
 I don't quite like those stories where there seems to be insta-love. Em is supposed to HATE Cas and his family yet she easily falls for this prince. Not only that, Cas is either very slow or just dumb since Em, who is pretending to be Mary, speaks FOR the Ruined. It should've been a HUGE lightbulb. All that aside, there weren't many twists and turns in this book that I couldn't predict. Obviously once Cas found out he's been "betrayed" by Em, he goes on a I MUST HATE HER rampage. His character is so easily moldable - up until the end. 
 However the ending did intrigue me a little because I'm hoping it may answer some questions I've had with this flawed book. (hide spoiler)] 
 However, I'm not sure if I'm picking up the next few books for this series. I'm not sure if it is labeled as fantasy but I'd label this as more romance than fantasy. Maybe romance set in a fantasy world.