Drums of Chaos Series by Jo Clayton, Kevin Andrew Murphy

When two magically linked worlds come together, the people of Glandair call it "the Settling" while those of Iomard call it "the Corruption." Call it what you will, it is a time when power shifts, magical abilities skyrocket, and anything can happen.A young girl on Glandair looks up from her household tasks to see an ominous wizard hovering in the air in her father's study, beckoning her to come to him... moreWhen two magically linked worlds come together, the people of Glandair call it "the Settling" while those of Iomard call it "the Corruption." Call it what you will, it is a time when power shifts, magical abilities skyrocket, and anything can happen.A young girl on Glandair looks up from her household tasks to see an ominous wizard hovering in the air in her father's study, beckoning her to come to him.A young man on Iomard discovers his forbidden magical abilities and cannot resist experimenting with them.Sorcerers on both worlds work their private magics and lay their intricate plots, scheming to take control of two worlds at once.And the beautiful Hero who can save both worlds knows nothing of their intrigue…or of the role he is destined to play! less

The two worlds of Glandair and Iomard move together magically once every generation. And though the worlds never touch, people with special talents can walk between the worlds -- with good intentions or evil designs. Cymel, a child on the world of Glandair, first realizes that danger threatens when she sees a strange wizard hovering in the air in her father's study, beckoning her. It is up to her to save both worlds from evil .. moreThe two worlds of Glandair and Iomard move together magically once every generation. And though the worlds never touch, people with special talents can walk between the worlds -- with good intentions or evil designs. Cymel, a child on the world of Glandair, first realizes that danger threatens when she sees a strange wizard hovering in the air in her father's study, beckoning her. It is up to her to save both worlds from evil ... as the rumble of the Drums of Chaos gets louder with every passing day. less

Three sorcerers plot separately to reach the Empty Place and defeat the Hero–and each other. Other great magicians do what they can to protect the Hero, and the whole world with him.Breith follows the white bird, knowing that she is really his transformed love, Cymel. The beautiful sorceress Hudoleth steals youth and beauty from the young women around her to keep the Emperor's attention. The Shaman lies hidden in the Earth near the Empty Place... moreThree sorcerers plot separately to reach the Empty Place and defeat the Hero–and each other. Other great magicians do what they can to protect the Hero, and the whole world with him.Breith follows the white bird, knowing that she is really his transformed love, Cymel. The beautiful sorceress Hudoleth steals youth and beauty from the young women around her to keep the Emperor's attention. The Shaman lies hidden in the Earth near the Empty Place. Tensions of love, of war, of power and of magic all mount with the beating of the drums. less