The Dark Crystal

Origin
The Dark Crystal, better known as the Black Crystal, is an object used by the Dark Kingdom during the first arc of Sailor Moon. The Dark Kingdom used this to find and recover the Seven Rainbow Crystals, as well as transforming the Seven Great Youma back to their original forms.

It was later used by a brainwashed Prince Endymion to capture and contain the human forms of the Seven Great Youma, in the hopes of restoring them to their original forms and combining them into one powerful monster capable of destroying the Sailor Senshi.

Effects
This Crystal, initially created by a fan, absorbed what the Dark Kingdom was about: energy collection. The Crystal, when exposed to groups of people numbering ten or more, begins to absorb energy from them, usually without their knowledge. The more people surrounding it, the more energy it absorbs. After collecting so much energy, the artifact releases a monster called a youma, which attempts to further drain people of their energy.

After collecting so much energy, the Crystal begins to produce the Seven Great Youma, which are more powerful monsters than the previous iterations it creates. They are produced one at a time, and the next Youma is created when the current one is destroyed. If all seven are defeated, the Crystal will produce all of the Seven Great Youma at once, which will then merge into a single monster, a very powerful Youma which, if created, would be extremely difficult to defeat.

Collection
Collected from Tokyo in April 2016 by Agents Megan Wilcoxson and Myka Bering after reports of monsters attacking a museum led the pair to discover two people had planted the artifact in the museum, unaware of its eventual effects when activated for a long period of time.

Storage and Handling
Stored in the Convention Aisle on the shelf directly above the Sailor Moon artifacts relating to the transformation of the guardians.

Neutralizer gloves are mandatory. Avoid large gatherings of Warehouse personnel while handling this artifact or in its vicinity. If the presence is necessary, place the artifact in a small neutralizer box for the duration of the presence of the large group.

Trivia

 * The Crystal appears to be able to create the Seven Great Youma one after the other after collecting so much energy without the need to absorb more energy. Exactly how much energy has to be created is unclear, as it is unknown when the artifact was created and initially activated prior to its collection.
 * The youma created by the crystal are physically real, but cannot be defeated through normal means. The Tesla will not work on them, though some artifacts have proven effective against the youma.
 * The Sailor Moon artifacts have proven effective against the youma, as well as the Falchion sword.