I am a huge fan of The Iron Traitor, and I'm so glad I got an ARC of it! I liked The Iron Traitor a lot more than the Iron Prince, and while I wasn't completely sure about this series with The Iron Traitor, I've decided that it's just as interesting as Kagawa's Iron Fey series. 
 I really like the relationship Kierran and Ethan have, and it really reminds me of Puck and Ash. Their relationship is definitely complicated, and I'm really curious as to how their relationship will be different in the next one, given the huge cliff-hanger of an ending. Which is all I'm going to say about that. Actually, in general, I'm wondering how things are going to be in the next one, given everything that's happened in The Iron Traitor. 
 I really liked Ethan in this one, and while he still has some anger issues, I feel like he's calmed down since The Iron Prince. Not much, but a little, and I don't know if it's because he's grown on me, or he's changed or if it's because it's been a while since I've read The Iron Prince. At any rate, Ethan was a lot less irritating in The Iron Traitor, as was Kenzie (although there were times when she did get annoying). I did feel like the things Ethan learned in this book changed him a little. But for the most part, he's still him, even though he does have a better understanding of things that happened in the past. 
 I did feel like I got to know the characters so much better. They REALLY came to life in The Iron Traitor, and while bringing characters to life is something Kagawa is just good at in general, I felt like the characters really changed and came to life in this one. 
 And I'm glad we saw Puck and the rest of the gang, because things seem so much more lively when Puck and Grimalkin are around. I'm glad Puck and Ash and Grim were around to help out Ethan and Kierran, even though Kierran was acting like a moron the entire book. There were times when I was glad I was reading The Iron Traitor at work, because it ensured that I *wouldn't* be yelling at Kierran. Because I definitely wanted to a few times. I like Kierran's dedication and loyalty to Annwyl, but he also did some stupid things because of it. 
 Final Thoughts: The Iron Traitor really is a good addition to the Iron Fey series, and Kierran and Ethan are definitely the most interesting characters. I can't wait to read the next book, because I really need to know what happens! The Iron Traitor gets 5 stars. 
 *The Iron Traitor is from netgalley.com, which hasn't influenced my review in any way!