Embers of a Broken Throne

This is the fourth volume in Terry C. Simpson's epic fantasy series, Aegis of the Gods:

In the aftermath of a titanic battle, Ancel and the remnants of his people are fleeing to Benez, a city reviled by the world. Hunted by Tribunal assassins and shadelings, he must fight to see them survive even as corruption creeps across the land, and his father battles for sanity.
Ryne continues to hold fast to his secrets, but suspicious of those around him, he makes a shocking discovery of his own, one ...