According to Faragonda, in the first movie, the Obsidian Circle is said to be the secret entrance to a dark and terrible place, a black dimension of ultimate fear and hate, and that the gate of the Realm of Obsidian is what keeps evil distant, adding that this was the place where the Ancestral Witches were generated. When Bloom said that maybe her parents were there, Faragonda replied that it was preferable to hope otherwise as anyone who enters Obsidian is hopelessly lost, corrupted by absolute evil.
in the French dub, there are slight differences, as Faragonda says that the Obsidian Circle is the way to a dark, secret place full of sadness, a passage to a dimension ruled by fear, sorrow and bad luck and that the gate of that realm, the Obsidian Circle, is a terrifying symbol. She also said that all those who enter Obsidian are lost forever, destroyed by the darkest forces.
According to Flora, Obsidian is the nightmare realm where monsters and the most formidable creatures are all caged, and Faragonda precises that it is the story every child of Magix hears when he or she misbehaves.
It was mentioned by Musa as being a forbidden place and Tecna further commented in the French dub that even for those who did the most cruelties it was the most redoubtable and negative experience ever, and that Obsidian is a rock which annihilates powers of pure magic, sometimes definitely. In the Rai English dub of the first film, Tecna said that unless the Winx were made of pure gold Obsidian would drain their powers, making their chances of finding anything there exactly zero.
- Obsidian is a naturally occurring volcanic glass which of usually dark color which has been widely used throughout history to make blades and other cutting instruments.
- Obsidian is known to be the sister realm to Oblivion.