Shadow's Hidden Blade

The gods Light and Shadow created the world, and the millions of creatures that call it home. While they were equal in power, they were different in ability: Shadow was the creator of changelings, Light ruled over humankind. One day, the two gods fought. Their fighting caused destruction unlike anything the world had ever seen, especially because of the armies of magical super soldiers, called puppets, that each god created to fight for them. After horrific battling, Light defeated Shadow and banished Her. 

Over a hundred years later, a young changeling named Isabella lives surrounded by reminders of the war's devastation, but she has simply accepted it as part of her life. She is easily distracted by things like everyday delights, like the strange circus that comes to town one day...and shatters everything. Isabella's mother is murdered the night of the circus's arrival, and she's willing to do anything to find out who is responsible. 

Ursa has known no other life but the circus. It's a life of constant moving and chaos, carefully controlled by Ursa's best friend, the hyperactive ringmaster. Ursa knows the circus isn't perfect, but when a changeling named Isabella arrives and asks to be made a performer, it exposes a web of mysteries and lies bigger and deeper than anything Ursa ever could have imagined.

Now she and Isabella must work together to uncover the secrets kept from them for years, but there are people willing to kill to keep them hidden.