Evil Black Crystal is a crystal that grew with negative, dark energy.
Also known as the Malefic Black Crystal, is a crystal from the planet Nemesis that Death Phantom used to try and destroy the Earth. The Black Moon Clan intends to let it grow enough to open the Black Gate and allow the world to be destroyed. The leaders of the Black Moon Clan, with the exception of Saphir, wore earrings made of this crystal.
The people of Earth lived in peace in the 30th Century until the megalith, like a black monument appeared along with an explosion. It siphoned all of the energy and space became distorted. People began to vanish one by one due to the effects of that distortion.
The black monument destroyed Crystal Tokyo. It was used to invade Earth in the past.
The Black Crystal produces a distorted darkness, always expanding. The void devours all, people and buildings alike, reducing it to nothingness. And with a second Black Crystal Monument it's happening hundreds of times faster.