Hecate

Hecate is the goddess of magic, witches, herbology, and crossroads (most likely due to an association with crossroads demons). She is the goddess of both light magic and dark magic and everything in between. This includes necromancy: to power to summon and the control the dead. The undead are therefore also part of her domain: she is the lady of ghosts and spectres.

Hecate is the daughter of Perses and Asteria, making her the offspring of two Titans. She is not part of the twelve Olympians, yet she is worshipped by several large cults. Apart from the domain that she ruled over, she is also one of protectors of the household, together with Hestia, Zeus, Hermes, and Apollo. This strengthens here position in the Greek pantheon.

The story goes that she is a maiden, but that seems to be off. After all, she is rumored to be the mother of some famous offspring. Granted, the lineage of that offspring were all matters of dispute. They do make for a colorful bunch: a monster (Scylla), some ghosts (Empusa), a witch (Circe), and a famous prince (Absyrtus). Her mating partners included Apollo and King Ae√ętus, the latter making an appearance in the story of Jason and the Argonauts.