I am a huge fan of the fantasy genre. And assassins. Assassins rule. But I have to admit that I was seriously disappointed with this book. Sure, there are some things that I liked about it, but overall, it was pretty meh.
The good: I really liked the superpowers in this book. The power to control how another person perceives reality is so cool, but I found it hard to believe that Aron didn't know about his power until someone told him. One would think that a power you're born with would come naturally to you, but whatever. The characters also had a lot of potential, but I didn't really care for them. Aron is just your boring, bland male protagonist. He was nothing special, but he wasn't necessarily terrible. Dari, on the other hand, I couldn't stand. She's just a racist, self-righteous jerk. Yeah, the Fae almost drove your people to extinction. That sucks, but you don't have to be a jerk to everyone you meet, and you don't have to constantly point out how much stronger and more skilled you are than them. I liked Stormbreaker enough. He was pretty cool. My favorite, though, was Zed, mostly because he tackled a rock cat.
The bad: The world-building in this book is TERRIBLE. As soon as I started reading, it felt like I was reading the second book in a series. The author just throws in all of these things that the characters are familiar with, but are completely alien to the readers. Like the talons, for example. I went through the first eight or so chapters thinking that the talons were big birds because birds have talons, after all. But no, they're lizards! Giant lizards with wings! The author doesn't mention this until the fight with the rock cats. Another thing that the author doesn't explain until the fight with the rock cats is what the manes are. She says that they drain your blood or whatever, but she never mentions that they're ghosts until the characters are face-to-face with one. The author does this all. The. Time. Chevilles are mentioned constantly, but I had no idea what they were. It means ankles in French, but that still doesn't explain what they are. I just assumed that they were some kind of magical stone ankle bracelet until the author explained what they were.
Another thing that confused me was why everyone hated Stone. I can understand why somebody wouldn't want to kill for a living, but they're not so much assassins as they are social workers or police officers. They rescue abused children and innocents, they judge the wicked, and they keep the peace. Somebody has to do those things, even if those things are sometimes icky and bloody and not that pretty. Not everyone can be a pansy scholar.
The world of Eyrie is completely under-developed. There are dynasts, which are like kingdoms (which is what they should've been called because this world is vaguely Scotland-based, and Scotland had kingdoms, and I think that the author is confused about what dynasties are). Apparently, each dynast has its own mind-powers that have been all but bred out when the Fae (who I'm assuming are kinda like the Altmer in Skyrim) started doing it with their human slaves. That's all very nice, but that's not enough to make a world. Even if it's just one continent, there should be different languages, different religions, myths, legends, races, ethnicities. That's something that has always bothered me about fantasy and sci-fi worlds. They'll have one race, a god or a bunch of gods that they worship, and one language. That's not a world, that's a small region. Even within a country in our world, there are different dialects and different gods. The Greeks didn't all follow one religion, they worshiped hundreds of gods and had varying beliefs about who those gods actually were.