Hecate is the goddess of witchcraft. She's in a way like the triple goddess. Actually, Zeus did let her have power to give humanity what she wanted. But she also could take things away or withhold things from them.
Actually in Greek mythology she is always portrayed as a young goddess. Assigning a crone-like aspect to her is a modern invention.
Here's some information about her:
HEKATE (or Hecate) was the goddess of magic, witchcraft, the night, moon, ghosts and necromancy. She was the only child of the Titanes Perses and Asteria from whom she received her power over heaven, earth, and sea.
Hekate assisted Demeter in her search for Persephone, guiding her through the night with flaming torches. After the mother-daughter reunion became she Persephone's minister and companion in Haides.
Two metamorphosis myths describe the origins of her animal familiars: the black she-dog and the polecat (a mustelid house pet kept to hunt vermin). The bitch was originally the Trojan Queen Hekabe, who leapt into the sea after the fall of Troy and was transformed by the goddess into her familiar. The polecat was originally the witch Gale who was transformed into the beast to punish her for her incontinence. Other say it was Galinthias, the nurse of Alkmene, transformed by the angry Eileithyia, but received by Hekate as her animal.
Hekate was usually depicted in Greek vase painting as a woman holding twin torches. Sometimes she was dressed in a knee-length maiden's skirt and hunting boots, much like Artemis. In statuary Hekate was often depicted in triple form as a goddess of crossroads.
Hekate was identified with a number of other goddesses, including Artemis and Selene (Moon), the Arkadian Despoine, the sea-goddess Krataeis, the goddess of the Taurian Khersonese (of Skythia), the Kolkhian Perseis, and Argive Iphigeneia, the Thracian goddesses Bendis and Kotys, Euboian Maira (the dog-star), Eleusinian Daeira and the Boiotian Nymphe Herkyna.