Sapphire (SMCU)

Blue Sapphire is one of the members of the Black Moon Clan. He is the younger brother of Prince Diamond.

Profile
Sapphire is Prince Diamond's younger brother. Unlike the other members of the Black Moon Clan, he doesn't fight and only follows out his elder brother's orders.

30th Century
The four members of the Black Moon Clan 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
Sapphire is the one who knows how to build or decrease the power output of the Malefic Dark Crystal and he does so according to Diamond's wishes. Sapphire has been quick to point out Diamond's lover Esmeraude's faults. He also suspects their master, the Death Phantom, of having evil intentions and silently watches him. He soon discovers that the Death Phantom is only using Prince Diamond and plans to kill him once he is done. He is able to convince Rubeus about the Death Phantom’s intentions. Realizing that, the Death Phantom sent Esmeraude to execute Rubeus.

In an attempt to weaken the Death Phantom, Sapphire headed into a secret room at the Empire State Building and manages to steal the dark microchip to weaken the crystal’s power. However, he is attacked by Black Moon aliens sent by the Death Phantom. Sapphire manages to fight them off and escape, but is badly wounded in the process. Seiya Kou, a member of the Starlights, encounters the wounded Sapphire and bandages his wounds.

With the timely arrival of Tuxedo Mask, Sapphire attempts to warn his older brother about the Death Phantom, but even with Seiya attempting to help him, he was killed with two energy blasts from the Death Phantom. His head was bandaged by Seiya earlier, and when the bandage fell off, there was no dark crescent moon on his forehead, proving his firm transition to the side of good. Diamond is heartbroken when he sees Sapphire die and begins questioning the Death Phantom's motives.

Plight of the Firefly
The spirits of Sapphire and Diamond 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.

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.

Trivia

 * Sapphire’s birth month corresponds to sapphire being the birthstone for the month of September.