This book was okay. In my opinion, this was better than the previous one. 
 The ending was the best part of the whole book. (My thoughts back when I thought this was a series.) 
 But for a the last book of a series? I wish there would have been another book. Honestly, I DID NOT expect it to end there. The whole time I was reading it, even in the end, I expected another book after this. 
 I liked how Evin was realistic. He had a "careless" type of manner in the beginning, but he wasn't arrogant, and everyone saw him as goofy and cheerful, despite being the nephew of the person in charge of the Empire's school. He could have easily been, but he wasn't. He wasn't someone like Jace Wayland, and it was very refreshing. I vaguely remember someone leaving on a mission from the previous book, but the name "Arxis" didn't ring any bells. I also like how Cyn still tried to protect her sister even though they'd fight sometimes - and pretty violently too. (Sisterly love :P) 
 But Karyn. She was in charge of the academy. She single-handedly controlls it, yet somehow, she also fights rebels and travels all over the Empire, she teaches, or oversees the most advanced group in the academy (which she spends a lot of her time doing) and she... does everything? That part seemed unrealistic. She should have had other people helping her. It also said that the person who was in charge of the academy also controlled the empire? And I'm supposed to believe all of this? A board of the academy or a bunch of people in charge would have been more realistic. 
 The ending with Sorin? It should have NOT ended like this. And that scene with Sorin turning his back to the window is seared into my mind. >.< It's kind of like the author took the characters of the previous book, made them into minor characters, and presented new characters and decided to make them into the main characters. Cough, cough, *Evin*. He wasn't bad, but the ending was disappointing. I have to admit, the ending does kind of make sense though, rationally. 
 Also, the world building wasn't as invisible-ish and vague as it had been before. Maybe it's because the MC travels more in this. Idk, but maybe it would've been easier to understand if there had been a map. 
 This definitely needs another book after it.