The Sun Sword Series by Michelle West

The Dominion, once divided by savage clan wars, has kept an uneasy peace within its border since that long-ago time when the clan Leonne was gifted with the magic of the Sun Sword and was raised up to reign over the five noble clans. But now treachery strikes at the very heart of the Dominion as two never meant to rule--one a highly skilled General, the other a master of the magical arts--seek to seize the crown by slaughtering all of clan Leonne blood.

The uneasy peace within the Dominion's borders was shattered when treacherous forces seized the crown by slaughtering all members of the ruling Clan Leonne. Now, in a neighboring empire, the sole surviving heir to the throne, a young man never destined to rule, must prove his worthiness to claim the crown, even as his family's murderers and their sinister demonic allies plot his doom.

IN THE DOMINION --those allied with the demons of the Shining Court feared the bargain they'd made. For to the kialli betrayal was a way of life, and every action was a means to gain greater power. And as the Festival of the Moon approached, the demon kin began to prey upon those in the Tor Leonne. But more frightening than their presence was their "gift" for the Festival, masks created not by human craftsmen but by the kialli... moreIN THE DOMINION --those allied with the demons of the Shining Court feared the bargain they'd made. For to the kialli betrayal was a way of life, and every action was a means to gain greater power. And as the Festival of the Moon approached, the demon kin began to prey upon those in the Tor Leonne. But more frightening than their presence was their "gift" for the Festival, masks created not by human craftsmen but by the kialli. Even the magic and knowledge of the greatest of the Dominion's Widan had been unable to discern what trap the masks contained--and time to discover and avert this menace was running out....IN THE EMPIRE --the armies were mobilizing for war. But before they carried the battle to the Dominion, Seer Jewel ATerafin would be forced to follow her own destiny. For what she'd seen in vision she could not deny. And so Jewel, with only Avander to guard her back, would abandon House Terafin on the eve of its greatest peril and journey into the darkness which was fast overshadowing the mortal lands....AND AMONG THE VOYANI --the moment had come to make their final stand against Allasakar, Lord of the Hells, for they alone had kept to the old ways, guarding the ancient knowledge. But hounded by their enemies, and with one of their greatest treasures hidden in the Tor Leonne, could they withstand the power of the Shining Court? less

The ancient Powers have awakened, and new allegiances are forged. As the rightful heir of the Dominion seeks to overthrow the man who killed his entire family, the Voyani embark upon the Sea of Sorrows to find the lost Cities of Man—a journey that seems certain to lead to a deadly confrontation with the Lord of Night.

In the fifth novel of the Sun Sword series, acclaimed author Michelle West returns to a war-torn world of noble houses divided and demon lords unleashed...

Now, at last the Sun Sword has been delivered into the hands of its rightful owner, and the armies of the Dominion and the Empire are about to rendezvous for their final battle. But no one can know how the Lord of Night's daughter Kiriel will change both the nature and the course of the war. And no one can foresee whether mortals or the demon Kialli will prove the final victors.