Savage Storm by Tracy Falbe

Filled with righteous rage, Dacian and Onja spread violent chaos across two realms. In the tribal kingdoms of the west Onja sees a whole civilization that she must harness if the rys are ever to destroy the hated tabre of Nufal. No longer hobbled by dreams of rys and tabre unity, Dacian crafts enchanted weapons and trains the rys to fight. Onja commands Amar to raise an army. She ambitiously decides to abolish the religions of the western tribes and to install herself as their new Goddess. Aided by her magic, Amar daringly overthrows monarchies and celebrates with his outlaws in the palaces of the vanquished.
The servants of the rys revel in Onja’s grandiose vision, but the Nufalese humans and their tabre masters have barely begun to realize their danger. When Onja enthralls the savage Chatapaka people of the remote north and unleashes their brutal hordes upon vulnerable Nufalese settlements, the militia is overwhelmed. Cruce Chenomet and his comrades struggle to save the fleeing settlers. Cruce quickly loses hope but keeps his courage as he confronts the savage storm.