Inanna and Ereshkigal, the two sisters, light and dark respectively, together represent, according to the antique manner of symbolization, the one goddess in two aspects; and their confrontation epitomizes the whole sense of the difficult road of trials.
Campbell argues that Inanna and her underworld counterpart Ereshkigal are a single bifurcated deity whose confrontation constitutes the archetypal ordeal at the center of the hero's journey.
, The Hero With a Thousand Faces, 2015thesis