Gorgyra is the darkness of the river Styx, and she is also a dark nymph of the Underworld. She has been identified with Styx and could likely be acquaintances with her, and also has another name, for some people call her Orphne. She is not a goddess.
Gorgyra has a thing for trouble, as she's seen smiling commonly everytime, but she thinks evil people, full of sorrow deserve to smile as well.
Her official Greek names are Γοργυρα and Ορφνη.