Guardian of Fate & Vengeance (The Aurorian Triology #3) by Lacie M Lou:
 
Sides are drawn. Time is running out. War has come to Hevastia.

When Eliana receives an ominous warning, she is faced with insurmountable unite the Aurors of the other lands, find the Nine Souls Shield, and prepare an army in less than three months. Vaiccar’s power grows and his influence infiltrates the other lands of Odora with dire consequences.

Darkness surrounds Eliana and her allies on all sides. Birvat, the Auror of Leomaris, must travel to their homeland and confront an ancient evil in order to save their people and the Auror of Raephe, Isadora. Meanwhile, Joi, the Auror of Opulia, works to find a cure for a curse placed on Isadora. The Aurors of Aerethia and Laiken are trapped in service to a corrupt government, with no easy means of escape. Rena, the Auror of Meltise, searches for answers to the darkness sweeping across her homeland. Emmerrett, the Auror of Keladone, must unite his people against the threat of Vaiccar.

With Vaiccar's darkness closing in, who do you trust when it feels at times you can’t even trust yourself?