Magic's Pawn(1989)

Mercedes Lackey

Mage-Craft—

Though Vanyel has been born with near-legendary abilities to work both Herald and Mage magic, he wants no part of such things. Nor does he seek a warrior's path, wishing instead to become a Bard. Yet such talent as his if left untrained may prove a menace not only to Vanyel but to others as well. So he is sent to be fostered with his aunt, Savil, one of the famed Herald-Mages of Valdemar.

But, strong-willed and self-centered, Vanyel is a challenge which even Savil can not master alone. For soon he will become the focus of frightening forces, lending his raw magic to a spell that unleashes terrifying wyr-hunters on the land. And by the time Savil seeks the assistance of a Shin'a'in Adept, Vanyel's wild talent may have already grown beyond anyone's ability to contain, placing Vanyel, Savil, and Valdemar itself in desperate peril...