abysmal : low
Stygian is an adjective that references the River Styx. So, a Stygian Harpy would be a Harpy found in the Underworld, near the River Styx.
She was stygian in her appearance yesterday.
When the candle in the room blew out, it made the room appear Stygian, like a light bulb about to die.
To make Stygian Iron, you would have to forge it and then cool it in the River Styx, producing a keen, indestructible blade. Because it is cooled in the River Styx, only Hades and his children, God...