Caledon Series by Deborah Turner Harris

After the death of her brother in a battle against a shape-shifting demon, Mhairi takes up the struggle to unite the Caledonians and must use all her Feyan powers to overcome a tyrant's dark magic and regain her rightful throne.

From the bestselling coauthor of the Adept series comes the stunning conclusion to the historical fantasy saga of Caledon.

For centuries, the royal line of Caledon has been the guardian of the Anchorstone, a mysterious---and dangerous---artifact that commands the terrible powers of the Mist. But now, Queen Mhairi of Caledon and her nemesis, King Edwin of Beringer, are summoned to the City of Exile to end the war between their two kingdoms forever. In an unprecedented act of goodwill, Mhairi is prepared to give up possession of the Anchorstone. But the Berings have no such harmonious motives in mind... moreFor centuries, the royal line of Caledon has been the guardian of the Anchorstone, a mysterious---and dangerous---artifact that commands the terrible powers of the Mist. But now, Queen Mhairi of Caledon and her nemesis, King Edwin of Beringer, are summoned to the City of Exile to end the war between their two kingdoms forever. In an unprecedented act of goodwill, Mhairi is prepared to give up possession of the Anchorstone. But the Berings have no such harmonious motives in mind. Their wish to kill the queen, by summoning a demonic force so evil that it could disrupt the legacy of the Anchorstone---and destroy the future of the entire world... less