Mask of Darkness is a member Marik Ishtar's Rare Hunter organization. He is the Tag-Team partner of Mask of Light, and together they have Dueled with Seto Kaiba and Dark Yugi.
He, along with Mask of Light, was ordered by Marik Ishtar to Duel Seto Kaiba and Dark Yugi in a Tag-Team Duel. They were Dueling atop a skyscraper, and each player is standing on glass. The loser's glass will shatter, and will fall to the bottom of the skyscraper, killing the loser. During the Duel, Mask of Light and Darkness heavily relied on teamwork, unlike Kaiba and Yugi, and were using a "Mask" Deck, preventing them from Tributing monsters to summon Kaiba's "Obelisk, or Yugi's Slifer. However, Kaiba used "Soul Exchange" to tribute Yugi's monsters to Summon "Obelisk". He then defeated Mask of Darkness with "Obelisk". The glass shattered, due to him losing. However, he survived when he opened up a parachute to land on a pole.