The Wiseman was the real mastermind behind the attacks of the Negamoon. Often seen waving his hands over a crystal ball, he gave advice or orders if you will, to the others. He seemed to just be Prince Diamond's advisor, but he really had other plans for him and the rest of the Negamoon family. The Wiseman's real mission was to help his master the Doom Phantom to arise and turn the world into darkness.

He managed to convice Diamond that his own brother Saphire, betrayed him and fled to Earth with the key to the Black Crystal. He failed to mention that Saphire ended up on Earth after escaping Wiseman's wrath when he overheard him talking about the Doom Phantom and his plans. When others found out about his plans like, Saphire, or if they just got in his way like, Emerald, he simply had them killed off. It didn't take long before he offted all of them including Dimand himself. Leaving the Wiseman to fight the Senshi himself. With the combined power of both Sailor Moon and the newly good-again Reeny, he was defeated.