The Borderlands of Power by Tracy Falbe

Nufal is invaded and human warriors fight alongside their rys and tabre champions in a grueling clash of muscle and magic. Grim struggles smash strategy into chaos, and loyalties degenerate into desperate choices for survival. Tempet and Alloi, driven by their desire for revenge upon the rys, push King Shan deep into the violent reservoir of his power.

Still reeling in the aftermath of battle, Dreibrand Veta scrambles to assert his authority upon the remaining forces of the Atrophane Empire if he is to defend his land and overturn the censure that disgraces his name. Rebellion on the imperial frontier complicates these goals as does Shan's sudden unpredictability as an ally. Miranda braves the snows of the Rysamand Mountains to demand that Shan pay his debt to her by helping Dreibrand. Only ambition keeps despair at bay as forces vie for dominance in the borderlands of power.