Sky Trillium: Julian May

Book V of The Trillium Saga. Sisters Haramis, Anigel and Kadiya thought they had rid the world of evil, that the dark sorcerer Orogastus was banished to the Chasm where he would surely die. But after many years, Orogastus is stirring once more and the omens do not look good. Anigel's son, Prince Tolivar, has unearthed the powerful three-headed talisman and has plans of his own; Kadiya's talisman has lost its power; and the Archimage of the Sea is imprisoned in a slab of blue ice - apparently the work of the Vanished Ones. Without the combined forces of the talismans, the peace the sisters fought so hard for is at risk... Cover art by Geoff Taylor. https://cosmiccauldronbooks.com.au/p/black-trillium-marion-zimmer-bradley-julian-may-and-andre-norton/