Veran

Veran, the self-proclaimed Sorceress of Shadows, is the main antagonist of The Legend of Zelda: Oracle of Ages. She has the ability to possess others, and has done so to at least three characters: Impa, Nayru, and Queen Ambi. Her goal is to fill Labrynna with sorrow.

Veran is a voluptuous, teal-skinned human female who wears a flowing dress and a revealing purple armor-like top. Her shoulder pads bear the Gerudo Crest, which is also seen on Onox's chestplate. Whenever a character is under Veran's control, their skin color is changed to teal like Veran's. When not in possession of a host, but not in her physical form, Veran appears as a large, flaming black essence with glowing eyes.

The Legend of Zelda: Oracle of Ages
In The Legend of Zelda: Oracle of Ages, Veran met Link while controlling Impa's body, and she tricked Link into pushing a Triforce-marked boulder blocking the path to Nayru because Veran was deterred by the rock's symbol. Veran reveals herself and lets go of Impa to possess Nayru. Veran takes advantage of Nayru's powers to travel back in time and alter history. Veran deceived Queen Ambi and became her most trusted advisor. Veran then convinces Ambi to have the people of Labrynna work nonstop on the Black Tower in order to guide her lost love, Cap'n, home from the sea.

Link eventually manages to enter Ambi's Palace and face off against Veran, but she raises a point that if Link attacked her, only Nayru would bear the damage. During the battle, Veran can teleport and shoot fireballs in a spiraling arc around the room. When hit with a Mystery Seed, Nayru would fall asleep, causing Veran to leave her body. With the Switch Hook, Link can separate Veran from Nayru's body and leave her vulnerable to attack.

When Nayru was freed, Veran managed to take control of Queen Ambi and fled to the Black Tower. Once Link has collected all eight Essences of Time, he can go to the Maku Tree to obtain the Huge Maku Seed, allowing Link to access the Black Tower.

The final battle takes place on the top floor of the Black Tower. At first, the boss fight is fought similarly to the first one against Veran in Ambi's Palace, but Veran has the added ability to summon small spiders that attack Link. When Link manages to free Ambi from Veran's control using the Switch Hook, Veran transforms into a fairy-like being. She flies around the room spitting fireballs and creates four Dark Links, who act like Arm-Mimics, to accompany her. When Link defeats Veran's fairy form, the Black Tower begins to collapse. Just when Link manages to exit the Black Tower, Veran uses a Wallmaster to capture Link and has him face off against her a final time. In this part of the battle, Veran has three different metamorphoses including a giant turtle, a hornet, and a spider, all bearing her face. After a long battle, Link manages to defeat Veran, but not before she lit the Flame of Sorrow, one of the three flames that Koume and Kotake need to revive Ganon.