The "Black Moon Clan" is the main group of villains in the second arc in the manga and for most of the 2nd season of the Sailor Moon anime series.
They are an evil organization originating from Nemesis, the 10th planet of the solar system, in the 30th Century. Using the tremendously strong, evil powers of the Dark Crystal, they attacked Crystal Tokyo, pursuing the mighty Silver Crystal and turned all of the people into statues, and forced them into a comatose state of suspended animation, as well as the Queen herself. They eventually traveled back to 20th Century, pursuing the Rabbit.
The members of the Black Moon Clan have black upside-down black crescent moons on their foreheads in comparison to the Silver Millennium's golden crescent moon-shaped symbols. Also, the members of the Black Moon have diamond-shaped earrings made out of the tremendously dark and evil Black/Dark Crystal that allow them to teleport over large distances in a flash of darkness.
The Black Moon clan consists of mainly:
- Wiseman (mastermind/advisor)
- Prince Demande
- The Spectre Sisters
- The Boule Brothers
- Black Lady (temporarily)
Droids were units used by the Black Moon Clan. In the manga, all of the droids were all similar-looking in shape and form, and only able to produce screeches, while in the anime, they were all unique and were able to talk.
The Specter Sisters used the droids to fill a Crystal Point with dark energy. Esmeraude did the same thing but also ordered them to guard the Dark Wedge she implanted in the specific location.
Members of the Black Moon Clan originally lived on 30th Century earth before being expelled by Neo-Queen Serenity to the planet Nemesis. Wiseman took this as an opportunity to achieve his own goal of bringing darkness to the world and unleashing Death Phantom. He managed to manipulate all members of the Black Moon Clan to unknowingly support his self-interest by instilling hatred upon them and encouraging them to seek vengeance on Neo-Queen Serenity and to destroy Crystal Tokyo. Although Prince Demande was in control of the Black Moon Clan, Wiseman manipulated him behind his back.
The Black Moon Clan launched an attack on Crystal Tokyo, destroying everything except the Crystal Palace, which was protected by a barrier. Sailor Pluto sent the daughter of Neo-Queen Serenity and King Endymion, Chibiusa, to the past for safety.
Traveling Back in Time / Sailor Moon R
After Chibiusa was sent back in time to 20th century Tokyo by Sailor Pluto, the Black Moon Clan followed her, aiming to destroy her (which they call the Rabbit) and the Silver Crystal, as both were a threat to their plans. They arrived shortly after the Makai Tree Arc of Sailor Moon R. While in the present day, the clan also decided to conquer the earth of that time.
Crimson Rubeus was initially tasked by Prince Demande with the Rabbit and the Silver Crystal, commanding the Spectre Sisters and using droids to aid him. Every time Chibiusa tried to return to the future, the energy given off would lead the Black Moon Clan right to her location. Eventually, the Black Moon Clan very soon found themselves up against the Sailor Senshi, who protected the Rabbit.
While in the 20th Century, Rubeus additionally wanted to corrupt what would become the Crystal Points of future Crystal Tokyo, but all his attempts were undermined by the Sailor Senshi, something that disappointed the prince. Sailor Moon caused even more trouble for him after she turned each of the Spectre Sisters good. Esmeraude even mocks Rubeus for his repeated failures.
In a final attempt to prove himself worthy, Rubeus locates Chibiusa one more time and tries to capture her. Sailor Venus, Mercury, Mars, and Jupiter try to protect her but end up getting themselves captured by Rubeus aboard his spaceship. Sailor Moon and Chibiusa boards the ship. While Sailor Moon confronted Rubeus in battle, it provided a distraction, allowing Chibiusa to destroy Rubeus's power source (his dark crystal) and free the other Sailor Guardians. Rubeus sets his ship to self-destruct, to take the Sailor Senshi and Chibiusa with him, but the Sailor Senshi and Chibiusa put their powers together and teleports safely back to earth. Rubeus is killed in the ship's explosion.
Esmeraude took Rubeus's spot but didn't have any more luck than him in succeeding a mission. After the Sailor Senshi, Tuxedo Mask, and Chibiusa traveled to the future, Wiseman gave Esmeraude increased power. She took the form of a seemingly unstoppable dragon but was killed after the Sailor Senshi put their powers together.
Although Esmeraude was gone, Wiseman recruited a new member by capturing Chibiusa, whom the Sailor Guardians left alone in the Crystal Palace thinking she'd be safe and turning her to Black Lady. The Sailor Guardians tried on many attempts to turn Black Lady good again but Wiseman kept preventing that.
Saphir discovered Wiseman's true intentions after overhearing his plans and tried to warn his brother Demande, but was badly injured by Wiseman, forcing him to escape to earth. On Earth, he was cared for by the Spectre Sisters, before going out to again try to warn Demande. He managed to speak a few words to him but was finished off for good by Wiseman.
The Malafeic Black Crystal was sent to Earth, where it grew, collecting power to open the gate to the dark world for dark energy to enter the earth. The Sailor Senshi entered the Black Crystal, where Sailor Moon got separated and confronted by Demande. Although he tried to brainwash Sailor Moon, she spoke sense into him, allowing Demande to discover Wiseman's true intentions, realizing his brother was right. Wiseman attacked and Demande tried to counter him. Demande blasted Wiseman to pieces but he just came back and emitted a blast of dark energy that killed Demande.
Black Lady had enough dark energy to open a portal to the dark world. In a final battle, Sailor Moon transformed to Neo-Queen Serenity and finally managed to turn Black Lady to Chibiusa for good. It was too late, however, as the world was starting to turn to darkness under the dark powers controlled by Wiseman. Serenity used the Silver Crystal to counter the dark energy. She was joined by Chibiusa, who had silver crystal a part of her, along with the Sailor Guardians. Together, they destroyed the darkness and Wiseman along with it for good.
- In the anime, the Black Moon Clan shares several similarities with the Dark Kingdom:
- Like the Dark Kingdom, the Black Moon Clan also searched for the Silver Crystal, though with the intent to destroy it while the Dark Kingdom wanted to keep it to fuel its power.
- Esmeraude and Rubeus share a rivalry similar to that between Nephrite and Zoisite.
- Both turned the main protagonist evil. The Dark Kingdom brainwashed Tuxedo Mask while the Wiseman of the Black Moon Clan brainwashed Chibiusa, turning her to Black Lady.
- Both aimed to unleash an ultimate enemy and dark power upon the universe. Queen Beryl of the Dark Kingdom wanted to unleash Queen Metalia while Wiseman wanted to unleash the Death Phantom.
- Both originally come from different times. The Dark Kingdom is from the past and the Black Moon Clan is from the future (though the Dark Kingdom reemerged in the present day, while the Black Moon time-traveled to the present day). Both want to conquer present-day Earth.
- They are referred to as the Negamoon Family or the Realm of the Dark Crystal in the DiC English dub.