The Ghostly Ether is a location from The Legend of Zelda: Twilight Princess. It is a dream-like plain with Faron Woods, Death Mountain, Hyrule Castle, Arbiter's Grounds, and Snowpeak partially submerged in the distance. It is here that the Hero's Shade resides and teaches Link new Hidden Skills.
After Link finds a Howling Stone and communicates with the Hero's Shade through it, the entity enters the Light World as a Golden Wolf. Once Link meets up with the wolf, the creature transports Link and himself to the Ghostly Ether where he transforms into a heroic, armored skeleton. The Hero's Shade proceeds to teach Link a new Hidden Skill and once he has mastered it, Link is transported back to the Light World.