The First King of Shannara(1996)

Terry Brooks

After the terrible misuse of magic during the First War of the Races, the Druids at Paranor devoted themselves to the study of the old sciences. But dark forces were on the move from the Northlands, and it was left to Bremen and those few who supported him in his work with the arcane arts to stand against the enemy's seemingly-invincible Troll army. For at the heart of the evil tide was an archmage and former Druid named Brona...Using the special skills he had acquired through his own study of Magic, Bremen was able to penetrate the huge camp of the Troll army and learn many of its secrets. And he immediately understood that if the peoples of the Four Lands were to escape eternal subjugation they would need to unite. But, even when united, they would need a weapon, something so powerful that the evil magic of Brona, the Warlock Lord, would fail before its might...