Wise Man is responsible for the deaths of Esmeraude, Sapphire, and Prince Diamond himself. He's also the one behind Chibi Usa's transformation to Black Lady. He tried to deceive Sailor Moon as well, but was unsuccessful.

Wise Man used the Black Moon clan for his own goal: to plunge the world into darkness and summon the Death Phantom. The Death Phantom would then wipe out all life from the world and bring about Silence and Pureness.

In the end, when the Black gate was opened, Wise Man declared that HE is the Death Phantom. He battled Sailor Moon, who turned into Neo-Queen Serenity. She used the Holy Silver Crystal against him, but it was not enough. Chibi Usa cried, her tears formed yet another Holy Silver Crystal. Chibi Usa then transformed into Princess Chibi Usagi and helped her mother defeat Wise Man.