Persephone

Mythology
In Greek mythology, Persephone was the Queen of the Underworld, the korē (or young maiden), and a daughter of Demeter and Zeus. In the Olympian version, she also becomes the consort of Hades when he becomes the deity that governs the underworld.

In the series
Theresa's mentor and the queen of the underworld. She is tall, young, and possesses two distinct temperaments - one gentle and light-hearted, while the other, which is brought out when she is angry, is uncontrolable and spiteful. While enraged her surroundings become dark and her skin appears light-blue. To fulfill her ancient agreement, to spend half her time in the Underworld with her husband Hades, Persephone has in her solarium a secret passageway to his realm hidden behind The Four seasons. This passage allows the heroes access to the Underworld without fulfilling the usual requirement of being dead. She seems to be fond of gardening, not surprisingly given that she is the daughter of Demeter and a goddess of spring, whom she affectionately refers to as "Mommy". She also appears to share a loving relationship with her husband and their "puppy," Cerberus. Her connection to the supernatural and vast wealth (as a result of being married to Hades ) is something she shares with her affluent and clairvoyant student, Theresa