Umbra, known in the Japanese version as Mask of Darkness, is a member Marik Ishtar's Rare Hunter organization. He is the Tag-Team partner of Lumis, and together they have Dueled with Seto Kaiba and Yugi Muto. Umbra wears a black-colored, frowning mask on the left side of his face.
He, along with Lumis, was ordered by Marik Ishtar to Duel Seto Kaiba and Yami 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 (in the dub, a "vortex" will open, and the loser's mind will be sent to the Shadow Realm). During the Duel, Lumis and Umbra 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 Umbra's monsters, who were originally Yugi's monsters, to Summon "Obelisk". He then defeated Umbra with "Obelisk". The glass shattered, due to him losing. However, he survived when he opened up a parachute to land on a pole.
Umbra and Lumis play Mask-themed God Seal Decks, that weaken and manipulate the opponent's cards while lowering their opponent's Life Points. Umbra plays a Deck with more Monster Cards while Lumis plays a Deck with more Spell and Trap Cards. They also rely on teamwork to support each other, while taking down the opponents. When provoked by Kaiba, coupled with several slip-ups, their teamwork faltered, leading them to defeat.
- His name is Latin for "shadow".