I think there are several things wrong in this book: 
 1. the kickass heroine, because she kicks a lot of asses, but she never really wins any of her fights. only towards the end you can see her shifting into controlling her rage and hatred to be able not to do something stupid. but as good as she tells herself at the end the whole story and all the people dying in the end were kind of her fault. 
 2. the mysterious bad boy male character, aka love interest, because seriously? again? #facepalm. The way he slowly changes into a better person (spirit?) was interesting to read, but also predictable and in the end boooring (nothing new under the sun). 
 3. the love triangle that never gets to be one, but that it annoyingly feels like one until the middle of book, more or less. 
 4. Did I mention that the two guys in this book are super beautiful, hot and just perfect? *yawn* 
 5. the fact that the whole book goes about Ten not being able to decide which pledge she wants to make for her afterlife. although it is quite clear from the beginning, if only for the manners both realms show in recruiting souls. really I wasn't expecting any other ending, but the road to it annoyed me quite a lot due to the exaggerated amount of curves. 
 6. the world building, because it seems complex and I think the author put a lot of effort in trying to build something very unique and different and layered, but in the end it ended up being the eternal fight between good and evil (more precisely, between Hell and Heaven. Many Ends would probably be the purgatory). And the layers are the stereotypes for good and evil we have read multiples times everywhere. 
 7. the world building again, but this time, because the way it was executed was sloppy. the details are presented when needed (almost at the rate of a deus ex machina pro half chapter or more). especially because the firstlife world is very similar to ours( if not the same in a near fantasy future), so you as reader give some things for granted, but when those things appear the author decides the things don't work the way we expect "because I said so" (like the cell phones or the online newspapers, for example, but cars and planes seem to work normal). 
 but there were some things I did like: 
 1. the world building, yeah, I know, I've just said it was wrong done, but that doesn't mean it didn't intrigue me. in fact, it intrigued me so much that I ended up seeing the flaws XD 
 2. Archer, a great character, also quite arquetypal, but still charming and warm and fuzzy. And the reason I'm not interested in reading more books of this series. 
 3. gorgeous cover, right? 
 I had the impression before reading this book that this author was not really my cup of tea, and my supposition was right. The book is entertaining, but it has nothing especially charming, engaging or remarkable for me. It is just another fantasy book out there with another kick ass female character who doesn't want to feel but who falls in love with the mysterious new (hot) guy, as expected from the first second.