Wiseman appears as a hooded figure in a purple-black cloak. His hands are visible, and they appear to be dark multicolored. When his face was revealed, his head was a skull.
Wiseman was at one point a human being who lived in Crystal Tokyo and possessed dark powers which he used to unleash chaos to the populace and brainwash people to rebel against Neo-Queen Serenity. He was banished using the power of the Silver Crystal to the barren 10th planet named Nemesis because she couldn't kill him as a human being, Nemesis was then marked as the forbidden planet. From there, Wiseman merged his spirit with the planet and became one with Nemesis. He cloaked his decayed and crumbling human body, and went to Earth seeking revenge. He convinced residents that the 30th century utopia to become rebels and told them he wanted to destroy Crystal Tokyo, the reason behind this being that The Silver Crystal gave all of the residents immortality, which they were brainwashed to believe was blasphemy against god and unnatural as all humans are supposed to age and die. Thus the Black Moon Clan was born. He led them in an attack on Crystal Tokyo using the power of the Evil Black Crystal from Nemesis, as a result, Crystal Tokyo was left in ruins and Neo Queen serenity was placed in a coma induced state. The 4 Inner Guardians and King Endymion we're placed into suspended animation. After this, Wiseman told his followers to travel into Sailor Moon's past to obtain the Silver Crystal so that he could rewrite the future and have his revenge.
As it was shown, he cares little of his pawns and even kills Rubeus. When faced with a new conduit for power, in the form of Chibiusa, Wiseman makes her his Black Lady. When Demande comes to his senses and blasts the Wiseman, the decayed body shatters, but Black Lady only laughs and reveals that Wiseman is Nemesis. With all of his followers gone, and Black Lady reverted to Chibiusa Tsukino / Sailor Chibi Moon (manga), he creates a dark energy swirl to kill the Sailor Senshi. Sailor Moon and Sailor Chibi Moon attack the planet with a Double Moon Princess Halation and he is destroyed.
During Sailor Galaxia's flashback, she once overheard a "mysterious cloaked figure" referring to a place where all stars are born, telling her that the place was Sagittarius Star Zero. It is also revealed that Wiseman, like Queen Metalia, Pharaoh 90, and Queen Nehellenia, was an aspect of Chaos, who used the incarnation of Wiseman to manipulate to set Galaxia on the path to serving his goals.
Wiseman ordered the clan to find and destroy both Chibiusa (which they called the Rabbit) and the Silver Crystal, both being a threat to his plan. While in the present day, he also decided to conquer the earth of that time.
In the present, he found himself up against the Sailor Senshis, whom slowly brought down many members of the Black Moon Clan. After Esmeraude's final defeat, he managed to kidnap and brainwash Chibiusa to do his bidding, turning her into Black Lady. The Sailor Guardians tried on many attempts to turn Black Lady good again but Wiseman kept preventing that.
Saphir discovered his true intentions after overhearing his plans and tried to warn his brother Prince Demande, but Wiseman attacked him. Badly injured, Saphir escaped to earth, but was eventually finished off for good by Wiseman. Demande later also found out of his true intentions and in a battle against Wiseman, was also killed by him.
Wiseman sent 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 earth.
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. It was too late, however, as the world was starting to turn to darkness under the dark powers controlled by Wiseman, who revealed that he was the Death Phantom himself. 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.
Wiseman is the borrowed form and name of Death Phantom himself. Many years ago, in the time of Crystal Tokyo, Wiseman had become utterly distorted and consumed by pure negative energy and attacked the peaceful land of Crystal Tokyo. Originally being human, Neo-Queen Serenity could not bring herself to take his life. Instead, she had exiled him to the cut-off world of Nemesis.
Gradually, Death Phantom became even more sinister and eventually became one with the very planet itself. He obtained the Black Crystal and used it to persuade the few remaining people of the Black Moon clan to work for him, and wipe the supreme Silver Crystal from existence; as it was and is the only thing capable of rivaling the Black Crystal in strength.
Taking the identity of Wiseman, he convinced the Black Moon Clan in attacking Earth and with the Black Crystal, allowed them to travel back in time to invade Earth. When Sailor Moon, Tuxedo Mask, Sailor Venus and Chibiusago to Crystal Tokyo to save the kidnapped Senshi, Chibiusa eventually flees into the time stream and Wiseman finds her and controls her, turning her into Black Lady. When Sailor Moon frees her friends, they are confronted by the Black Moon Clan and Wiseman. Rubeus tries to flee, but Wiseman catches him and kills him. Wiseman takes Saphir and Demande into the core of Nemesis, and controls them. He accompanies the two, along with Black Lady in the attack on the palace. After Demande attacks Wiseman, they see only a skeleton and Wiseman reveals his true identity as Death Phantom, fully merged with Nemesis.
After Sailor Pluto dies from freezing time and Chibiusa is freed from Death Phantom's control and awakens as Sailor Chibi Moon, Demande in an attempt to makes amends for trusting him, puts himself between Death Phantom and Sailor Moon and Death Phantom's power overwhelms Demande, vaporizing him. Sailor Moon uses her power, seemingly vanquishing Death Phantom, but had disappeared, along with Tuxedo Mask. The couple appeared in the outer reaches of the system where they see the real Death Phantom and Sailor Chibi Moon teleports and joins them. Sailor Moon and Chibi Moon use their power and finally destroy Death Phantom for good.
He has total power over the element of darkness, shadows, chaos and the shadow realm itself. He possesses the incredibly strong prophetic ability to see into the distant future, and foresee the outcome of certain events. He has complete control over the supremely powerful Malefic Black Crystal he has, and utilize its evil abilities to vast proportions of destructive energy.
- The German dub of the anime translated his name rather literally as Der Erleuchtete (the enlightened one).
- He shares the same English voice actor as Jadeite in the original DiC dub. This has led to some fan theories that Wiseman is in fact Jadeite in the future.
- He is one of two primary villains defeated before the ending of his respective arc. The other being Pharaoh 90.
- He and Esmerade were the only main villains of the Black Moon Clan to be killed by the Senshi.
- In the DIC dubbed version of the anime, his true identity, the Death Phantom, is called the Doom Phantom. In the Viz dub, he retains his name.