Diamond (SMCU)

Prince Diamond is the leader of the Black Moon Clan who oversaw the large attack on Crystal Tokyo in the 30th Century.

30th Century
Prince Diamond led the Black Moon Clan to attack Crystal Tokyo in the year 2923. Eventually, he shifted his attention to conquer the past, specifically the 21st Century. The four members of the Black Moon Clan, along with their alien leader the Death Phantom, enter the Door of Space Time to get to the year 2015 and retrieve a gigantic shard of the Malefic Dark Crystal in New York City.

Tuxedo Mask: The Last Starlight
In 2015 New York, Diamond first sent Rubeus to claim the Dark Crystal, but Rubeus was defeated by the masked vigilante known as Tuxedo Mask in a motorcycle chase. Esmeraude was then sent by the Death Phantom after she was ordered to execute the traitorous Rubeus, but her plans are foiled by the timely arrival of Seiya Kou/Sailor Starfighter, leader of the Starlights. It is later revealed that Esmeraude was in love with Prince Diamond. Later, Diamond's younger brother Sapphire found out that the Death Phantom was only using them for his own twisted goals, and attempted to warn him, but was killed by the Death Phantom.

In the meantime, he battles Tuxedo Mask and nearly succeeds in overpowering him, but then Tuxedo Mask is able to warn him that Sapphire's dying words are right and he is being controlled by the Death Phantom. Enraged, he turns on him up learning that he had killed Sapphire in trying to warn him about the treachery. When the Death Phantom directed two dark energy blades at Tuxedo Mask, Diamond jumped in front of him and took the hit, and died as a result of this injury. However, he was able to damage the Death Phantom with his Diamond Eye, shattering his arms, but the Death Phantom reverts to his true, ethereal form.

Plight of the Firefly
Now free from the Death Phantom’s control, the spirits of Diamond and Sapphire are channeled by Calaveras, a former, healed Black Moon Clan member, at a secret room in the Ayakashi Sisters' cosmetic shop in Dysnomia, allowing them to converse with the rest of the Ayakashi Sisters and the Outer Senshi. Diamond tells the Outer Senshi about the incoming threat of the Phantom Dimension's wormholes and that the Black Moon Clan's home planet, Nemesis, was sucked into one of them.

Sailor Crusade
The spirits of Diamond, Sapphire and Rubeus are summoned once again by Calaveras when the store was attacked by the Shadow Galactica Legion. The spirits later joined the battle in the Second Sailor Crusade.

Powers

 * Diamond Eye - His Black Moon symbol on his forehead becomes a third eye, which is able to stun and control his victims. He is also able to fire powerful energy blasts from his hands.

Trivia

 * Diamond’s birth month (April) corresponds to diamond being the birthstone for the month of April.