Sahasrahla dared Link to retrieve three Pendents. Each was guarded by a fierce creature, so the challenge was not to be taken lightly. Sahasrahla rewarded him when he returned with the first Pendents by telling him about the Master Sword, which only a proven adventurers could wield. Once armed with the Master Sword, Link could challenge Agahnim in the Castle Tower.
A Shrouded Maze
According to the legend, Princess Zelda was taken by Agahnim to the top of the Hyrule Castle Tower. In the darkened halls there, enemies attacked without warning. Many a would-be rescuer fell victim to their ambushes, but those who used their Lantern could light the room to face their foes. Agahnim was said to practice his evil magic at the top of the tower.