I love that there are a variety of landscapes and different races of people from the Chinese-style land of Zhong to the Australian landscape of Stetriol. It makes it interesting to have a different backdrop for every character in the beginning.
Each character also has a different life style. Meilin is the daughter of a highly respected general, Conor is the son of a farmer and the servant of a local lord's son, Abeke lives in a drought-ridden village in the savanna and Rolland is a homeless street urchin. Each has a different perspective on life and their new animal companions. The four are thoroughly different in personality, from sarcastic Rollan to arrogant Meilin. As the novel continues they all development and grow just a little.
I love the magic of the spirit animals, frankly, I would love to have one! The animals can go into a dormant state, becoming a tattoo on their human's body. They may not be able to talk as such but they can lend strength and skill to their human whilst having their own way of wordless communication. This is something I think anyone who has ever owned a pet can easily relate to.