The Sworn (Fallen Kings Cycle‪)‬

As plague and famine scourge the Winter Kingdoms, a vast invasion force is mustering from beyond the northern seas. And at its heart, a dark spirit mage wields the blood magic of ancient, vanquished gods.

Summoner-King Martris Drayke must attempt to meet this great threat, gathering an army from a country ravaged by civil war. Neighboring lands reel toward anarchy while plague decimates their leaders. Drayke must seek new allies from among the living—and the dead—as an untested generation of rulers face their first battle.

Then someone disturbs the legendary Dread as they rest in a millennia-long slumber beneath sacred barrows. Their warrior guardians, the Sworn, know the Dread could be pivotal as a force for great good or evil. But if it's the latter, could even the Summoner-King's sorcery prevail?