This was an amazing book. I really enjoyed Wist's writing style. Her writing style is to the point but leaves room for beautiful description. She also excelled at the action scenes; they were awesome, with enough danger and gore to make them believable but without overdoing it.
Sybl is an excellent character who really is just a normal girl caught in extraordinary circumstances. She doesn't whine, she just does the best she can and through her wits and caring nature she accomplishes a lot. Cirrus and Kas are also excellent characters, both of them have deep, dark pasts that make their characters at times tender and at times very dangerous, sometimes even bordering on evil.
The magic concepts Wist uses are unique. I loved how 'Thread' was used for various needs, including shapeshifting. I enjoyed how some human advancement in technology ties into it all giving it a light sci-fi edge.
Overall this blows away most of the other young adult fairy literature that I have read and I look forward to reading more by S.J. Wist!