Hecate is the triple headed greek goddess of magic, night, moon, ghosts and necromancy and resides in Hades as a sort of third wheel to Persephone and Hades.
Though she does not have many myths assigned specifically to her, I felt some heartbreak in what little information is available. Here is a goddess who delights in the macabre, and would be the perfect bride for the God of the underworld---and yet he is in love with Persephone (the daughter of flowers, life, and good harvests) who detests him in every way. And yet she stays faithfully in hell, sheparding and sorting out the dead souls--watching Hades and persephone all the while. Perhaps someone could write a good story for her?