Umbra (Mask Of Darkness) is the tall and thin one with the black-colored, frowning mask on the left side of his face. Underneath his Rare Hunter hood, he has short blue hair.

Yu-Gi-Oh! Duel Monsters centers around the journey of the spirit of an ancient Egyptian pharaoh who is trying to re-discover who he was many years ago, since he has lost his memories. With the help of a boy, Yugi Mutou, the one who awakened the spirit, and his friends, he battles many villains and adversaries. Many of the villains have been linked to the Nameless Pharaoh's past, due to the Millennium Puzzle he holds and many try to take the puzzle and his power away from him. 
The series focuses on the card game aspect of it and the main theme represented throughout the series is friendship.

Belgian actor, musician, and voice actor. 

10th grader Yugi spent most of his time alone playing games--until he solved the Millennium Puzzle, a mysterious Egyptian artifact! Possessed by the puzzle, Yugi becomes Yu-Gi-Oh, the King of Games, and challenges evil-doers to the Shadow Games--weird games with high stakes and high risks! These graphic novels contain new stories not seen in the anime, including the origin of Yugi and his friends!
 
(Source: Viz Media)
 
Notes: 
- The Viz Media release split the series into three parts with separate chapter/volume counts. "Yu-Gi-Oh!" includes volumes 1-7, "Yu-Gi-Oh!: Duelist" includes volumes 8-31, and "Yu-Gi-Oh!: Millennium World" includes volumes 32-38. 
- The final chapter of Viz Media's "Yu-Gi-Oh!" was moved from its final volume to the first volume of "Yu-Gi-Oh!: Duelist."

Yami no Kamen