Demodicus

Princess Salbeath has lost her father and brothers in battle and must flee her home with her protector and uncle, the great wizard, Fiane. There is sanctuary waiting in her grandmother's kingdom of Tsocathlan, the rose city in the caldera. On her way there, they rescue Prince Clent, the heir to one of the Six Kingdoms which the monster Halent has reduced to ruins. Clent and his people hide beneath a mountain, safe from Halent's army; but they live in constant fear and are longing to see the outer world again.
But they are reluctant to accompany Salbeath to Tsocathlan as Halent has spread falsehoods about Calupina, Salbeath's grandmother, and her people, calling them evil witches. Salbeath is a powerful, if untrained adept, and under her grandmother's tutelage she is able to unlock her powers. But Salbeath is not content to hide in the secure comfort of Tsocathlan; she intends to raise an army to free her people in Ranal.
She plans to find Halent's flaws and so defeat him. But Halent is confident in his power and believes she can never best him. He has kept Ranal whole so that he can entrap her there, marry her and have a family. He knows that Salbeath has great power - even more than the acclaimed Calupina - and that she will make a perfect wife for such a being as himself. For Halent is a Demodicus, a minor being from the Spirit World, and he intends to take Salbeath and her friend, an acolyte called Tarn, to the Spirit World for his pleasure and their punishment.
That is his first mistake. For Salbeath will never give up fighting to free her people from the tyrant. She must first overcome him and then send a weakened Demonicus back to The Spirit World in the hope he will never return.