Hekate [Hecate] is the liminal goddess and witch whose origins perhaps begin
as Carian. Hekate was first thought to be ubiquitous and harmless, but later, after the 5th century, she took on more sinister motivations. Hesiod described Hekate as once being Iphimede [Iphigenia], King Agamemnon’s daughter, though Homer does not mention such attribution in the Iliad. According to Hesiod and the Hekate/Iphigenia [Iphimede] legend, when Agamemnon, frustrated by the delay in getting to Troy, sought to gain favorable winds, he offered Iphigenia as sacrifice, but it angered Artemis and at the last moment, she replaced Iphigenia with an eidolon, an apparition, and brought Iphigenia into the cult of nymphs where Iphigenia prospered and in time, gained her own following becoming the divine and sinister presence so often attributed to her after the 5th century. “She is more at home on the fringes than in the centre of Greek polytheism. Intrinsically ambivalent and polymorphous, she straddles conventional boundaries and eludes definition” (Hornblower).
Hornblower, Simon and Antony Spawforth. The Oxford Classical Dictionary, Third Edition Revised. Oxford University Press: Oxford, 2003.