The Blending Enthroned Series by Sharon Green

Lorand, Rio, Vallant, Tamrissa, Jovvi, and Naran assume the leadership of the fledgling republic, and face dark intrigues among their own people, sinister plots by foreign powers, and a malevolent evil enemy of extraordinary power.

In the empire of Gandistra, a mystical union of elemental magics reigns...Lorand, Rion, Tamrissa, Vallant, Jovvi and Naran have combined their elemental powers and their deep compassion to bring a new era of enlightenment to their once enslaved land. The miraculous reforms decreed by the Ruling Sixfold Blending have enabled all to freely pursue the Limits of their magic. But freedom is a hated thing to some, giving rise to jealousy, deceitfulness and unchecked ambition... moreIn the empire of Gandistra, a mystical union of elemental magics reigns...Lorand, Rion, Tamrissa, Vallant, Jovvi and Naran have combined their elemental powers and their deep compassion to bring a new era of enlightenment to their once enslaved land. The miraculous reforms decreed by the Ruling Sixfold Blending have enabled all to freely pursue the Limits of their magic. But freedom is a hated thing to some, giving rise to jealousy, deceitfulness and unchecked ambition.As traitors scheme at home, the Chosen Six are called beyond Gandistra's borders to deal with a dire threat to their empire and their world. For, as the leaders of neighboring Gracely bicker and brood and play politics, an inconceivable army is massing -- an invading wave of impossible terror, dedicated to the total devastation of everything in its path. And it may already be too late to stop a foe immune to every known magic -- including the awesome blended might of Earth, Air, Fire, Water, Sight, and Spirit. less

Even with their combined Elemental powers over Earth, Fire, Air, Water, Spirit and Sight, Lorand, Rion, Tamrissa, Vallant, Jovvi, and Naran are hard-pressed to defend Gandistra against both its internal and external enemies.