What is the main conflict in The Sword of Shannara by Terry Brooks?

The Sword of Shannara by Terry Brooks is a fantasy novel that follows a group of people brought together to retrieve the magical Sword of Shannara, which is the only weapon that can defeat Brona, the evil Warlock Lord. The only person who can wield the Sword is Shea, who does not even believe the tales about Brona. When his family is threatened, Shea reluctantly joins the quest to find the Sword and destroy Brona.