I was amazed by the complex and beautiful world-building.
And the many layers of personalities, cultures, and people added more to the colorful palette of this story.
I found myself heavily invested in the characters as they fought against the evil that was taking over their world....and as they fought against the evil in themselves. But throughout it all, love, kindness, compassion shown through. And how sacrifices are sometimes made in order to save not just a person, but the entire world...enemies and friends included.
I highly recommend Shifter. This is a book I return to quite a bit when I'm in the mood to read, but not wanting to start anything new.