Hal Jordan's enemies: Warlock of Ys

When Zatanna was searching for her father Zatara, she reached the Other Side of the World and found the Warlock sending a magical creation to lure Green Lantern (Hal Jordan) there, or he believed only the power ring could enable him to enter earth's universe.

Working together, Zatanna and GL defeated the Warlock, leaving him alive but motionless and stripped of his magical powers. Yet he had worked one last spell, causing his and Hal Jordan's life energies to slowly transfer, so that a few years later they changed places. GL minus his ring was motionless in the Warlock's tower, while the Warlock was posing as Green Lantern. Zatanna was placed under a spell to keep her from warning anyone else what had happened.

However, she managed to alert some members of the JLA and they tracked down The Warlock and freed Green Lantern. The real Green Lantern and the Warlock then exchanged places and the Warlock was powerless once more.