Circe

"You, my dear, have the makings of a sorceress. Like me."

- Circe Circe is a minor Greek goddess of magic, (or sometimes a witch, enchantress, or sorceress) living on the island of Aeaea. She is the daughter of Helios, the Titan of the sun. Her mother is said to be Hecate in The Sea of Monsters.

History
Circe's parents were Helios, the Titan of the sun, and Hecate, the goddess of magic. Circe transformed her enemies, or those who offended her, into animals through the use of potions. She was renowned for her knowledge of drugs and herbs. Circe also purified the Argonauts for the death of Apsyrtus, as related in Argonautica, may reflect early tradition. In Homer's Odyssey, banished by the gods, Circe is described as living in a mansion that stands in the middle of a clearing in a dense wood. Around the house prowled strangely docile lions and wolves, the drugged victims of her magic; they were not dangerous, and fawned on all newcomers. Circe worked at a huge loom. She invited Odysseus' crew to a feast of familiar food, a pottage of cheese and meal, sweetened with honey and laced with wine, but also laced with one of her potions, and she turned them all into pigs with a wand after they gorged themselves on it. Only Eurylochus, suspecting treachery from the outset, escaped to warn Odysseus and the others who had stayed behind at the ships. Odysseus set out to rescue his men, but was intercepted by Hermes, who gave him the holy herb moly to protect himself from Circe's potion and, having resisted it, he told him to draw his sword and act as if he were to attack Circe. From there, Circe would ask him to bed but Hermes advised caution, for even there the goddess would be treacherous. She would take his manhood unless he had her swear by the names of the gods that she would not.

The Sea of Monsters
Circe ran a magical beauty salon on an island in the Sea of Monsters. She was extremely glamorous, and sometimes went by the alias of C.C. Although she treated females to a spa treatment, she turned all males who came to the island into guinea pigs. She formerly turned them into actual pigs, but found them too hard to manage. She had captured Blackbeard and his crew mates and kept the ships in harbor. When Percy Jackson and Annabeth Chase came, she turned Percy into a guinea pig by tricking him into drinking a magic potion. When Annabeth found out, she used Hermes' multivitamins to become immune to Circe's sorcery and free Percy from his curse and make their escape on the Queen Anne's Revenge. When trying to save Percy, she couldn't tell which guinea pig was Percy, so she stuffed all of the multivitamins in the cage, freeing all of the pirates that were also captured.

The Battle of the Labyrinth
Annabeth and Percy reminisce about their previous encounter with Circe, with Annabeth saying to Percy that he made a "cute guinea pig" much to his chagrin. She then gives him a hint that she likes him, which Percy does not understand.

The Lost Hero
Medea mentions that Circe is her aunt, and that she taught Medea to charmspeak.

The Son of Neptune
It is revealed that Reyna and her sister Hylla were at C.C.'s Spa and Resort when Percy and Annabeth were there. After Annabeth gave the pirates Hermes' Multivitamins, they were immune to magic and took over her island.

The Mark of Athena
When Chrysaor captures the crew of the Argo II he mentions selling Hazel Levesque and Piper McLean to Circe to help at her spa. However he was unsuccessful.

Appearance
Circe is described as a beautiful woman with piercing green eyes and long dark hair braided with threads of gold. She wore a silky black dress which had shapes that moved with the fabric, like animal shadows.

Abilities
Sorcery: Circe is a goddess-level sorceress. As the daughter of Helios she might have had the following abilities:
 * Alter Minds: She can alter minds.
 * Energy Blasts: Fire destructive energy blasts.
 * Illusion Casting: Creating illusions.
 * Matter Transmogrification: Transform objects and beings.
 * Projective Animal Metamorphing: Her "signature move" is transforming men into various animals.
 * Teleportation: The ability to teleport from one place to another.
 * Telekinesis: The ability to move objects with one's mind.
 * Agility: She moves with a prodigious agility that resembles a snake.
 * Charmspeak: She can convince people what to do even if they don't want to. Taught it to her niece, Medea.
 * Pyrokinesis: The ability to create and manipulate fire.
 * Foresight: Seeing the past, present and future. This seems to be the case as her niece, Medea, a legacy of the sun titan had this gift.
 * Photokinesis: The ability to manipulate light.
 * Chronokinesis: The ability to manipulate time (Helios presided over the measurement of time).
 * Thermokinesis: The ability to manipulate temperature (pyro- and cryokinesis rolled into one).

Trivia

 * Mythology states Circe's parents were either Helios and Perseis or Aëtes and Hecate, while in the books it seems to be Helios and Hecate. Rick Riordan might have made a mistake there.
 * In The Mark of Athena, Chrysaor planned on selling Hazel and Piper to her as slaves or trainees. It is unknown however if Circe managed to take her island back from Blackbeard sometime after Reyna and Hylla left, or possibly she opened a new spa.
 * Circe has been mentioned in every book of The Heroes of Olympus series released so far.
 * Pasiphaë is Circe's half-sister