This book is fascinating. The world building is fairly good, the arguments of free will versus predetermination are well handled and it's very well written. There are a couple of missteps in the narrative but I found the book to be a fairly gripping, swift read.
I found Enael to be an fascinating character, complex and slightly dismissive of her charges, she goes through a great deal in this novel and emerges a lot stronger than she does at the beginning.
Kaspen is interesting but he needed a little more fleshing out. I thought his emotions flip flopped a little more than necessary.
In the negative, I found the Kaspen/Enael romance to be fairly bland and without much spark. Even though the author tried hard not to do 'insta-love' it still felt under-developed and feeble. Their sensual scenes were extremely tame in contrast to other scenes within the book. In a book where you're supposed to root for such an obvious pairing, it's kind of strange that the hottest scene in the entire book is between two enemies. Well for me it was and I would have loved the author to have actually explored that angle a little further.
I will certainly read the next book in the series and I definitely recommend this book.