Death Phantom, who goes by the name Wiseman, is an immortal manifestation of Chaos from the future. In the English anime dub, he's called Doom Phantom instead.
The manga version tells a different story about his origins. Death Phantom started out as a human living in Crystal Tokyo during the 30th century, wielding dark powers—deadly hands capable of striking from impossible distances, and an evil gaze that let him control minds just by looking at people. Neo-Queen Serenity banished him to Nemesis, a barren tenth planet, as punishment. Over time, he merged his spirit with the planet itself, becoming one with it. His decayed body hidden, he began reaching out psychically to Earth, searching for anyone dissatisfied with Crystal Tokyo's immortal society. He convinced them that the kingdom was an abomination against nature, and thus the Black Moon Clan was born under his influence.
As Wiseman, Death Phantom led them into a devastating assault on Crystal Tokyo and then pursued them into Sailor Moon's past to steal the Silver Crystal and take his revenge. He uses his followers ruthlessly—manipulating them into suicide missions and killing Rubeus without hesitation. When young Chibiusa becomes available as a new power source, he corrupts her into Black Lady. Even after Demand turns on him and shatters his decayed form, Wiseman reveals the truth: he is Nemesis. When the Sailor Senshi finally attack the planet with a Double Moon Princess Halation, he's destroyed for good.
The anime takes a slightly different approach. Wiseman first contacted Prince Demand when he was much younger. The Black Moon Clan were actually descendants of traitors exiled to Nemesis centuries ago by Neo-Queen Serenity and King Endymion. Posing as Wiseman, Death Phantom manipulated them with promises of gaining amnesty for their people—but his influence gradually twisted them into serving his plan for revenge and Earth's destruction. He mentors Rubeus throughout his campaign but shows no genuine concern when the man dies. He humiliates Esmeraude when she asks to be queen of Nemesis, which transforms her into a dragon and kills her. He also tampers with Chibiusa's memories to create Black Lady, and murders Saphir once the man realizes he's been deceived. In the end, Death Phantom is destroyed, though Nemesis and its population survive.
Content compiled by AnimeList.moe from publicly available sources.
