The raven tower - Ann Leckie

Listen. A god is speaking.
My voice echoes through the stone of your master's castle. The castle where he finds his uncle on his father's throne. You want to help him. You cannot.
You are the only one who can hear me.
You will change the world.

A triumph of the imagination, The Raven Tower is the first fantasy novel by Ann Leckie, New York Times bestselling author and winner of the Hugo, Nebula, and Arthur C. Clarke Awards. Gods meddle in the fates of men, men play with the fates of gods and a pretender must be cast down from the throne in this breathtaking fantasy masterpiece.