uses Nature Civilization cards, but tends to use Shield Triggers from all 5 civilizations. A midget in a pink bear suit and is always seen sucking a pacifier and an 8-year-old boy. He rides around in a motor baby carriage and uses a Water Civilization deck, he is a skillful duelist and has even defeated Mimi (a powerful duelist in her own right) fairly easily. In Season 3, he uses a Darkness/Water deck, he also withdraws from the tournament after losing to Yumama. Dr. Root is a mad scientist who is Boy George's boss and an expert duelist. Outside of that, he also a human-resembling robot named Mr. Perfect and a pilotable giant robot. His eccentric methods always have some hidden lesson to help Shobu and his friends. Dr. Root's real name is Leroy. In Duel Masters Zero, he takes charge of training Shobu and his friends. He has a deck of Survivors in season 1 and in charge he has a Darkness/Water deck similar to Boy George's deck. NAC is a manga only character. This character is loosely based on , a Japanese card game player who became one of the top Magic: The Gathering players in Asia. He was involved in the making of "Duel Masters", assisting Dai Matsumoto (the manga author's nickname) as a technical advisor (the manga's plot is based around Magic: The Gathering). He has appeared in the manga both as NAC and as a more realistic cameo of himself known as "Nakamura-san". According to one of Dai Matsumoto's omake sections in the manga, NAC was also involved in the development of the Duel Masters card game. Knight is Shobu's mysterious and soft-spoken mentor. In the English "dub", his inner monologue is a source of much of the show's mature and subtle humor. Despite being Shobu's mentor, he is usually unable to assist his student in times of need due to either Shobu's stubborn attitude or Knight being unable to show up at the scene (such is the case in Shobu's duel with Hakuoh, when Knight reveals he never taught Shobu about dueling against the Light Civilization). Knight does not appear in the manga, although the manga character NAC is similar to him. On one occasion, Dr. Root had Knight take on a "Dragon Mask" persona to duel Shobu in order for him to reclaim his tournament pass. Knight's character is loosely based on the