Duel Master is a title given to those who have conquered and mastered the game of the same name.
Shobu Kirifuda's Era
A Duel Master is considered to be outrageously and terrifyingly strong, much more so than any other Duelist.
The very first Duel Master was Yaesar, who, just before his death, used his power to divide the Duel Master's Proof into seven fragments and scattered them the world over, leaving them in the hands of children. Duel Masters are able to resonate their talents with one another. A Duel Master is able to tell when another Duel Master is nearby.
During the events of the Fighting Edge manga series, Toy, Horus, and Esmeralda were taken captive by the Fua Duelists. All of the Duel Masters gathered during the World Tournament held in Japan. After Shobu defeats Zakira in the battle of fate, Shobu refuses to kill Zakira even though he had the chance to in the True Duel due to his belief that all life is important and that no one should die in the duel, the 7 fragments of the proof gather, releasing the young masters from their duty and the proof was reformed from the fragments. Due to the Proof recognizing Shobu as the true Duel Master due to his virtue and answer, it spreads its power, meaning that it was shared among others. The main proof then fell into a dormant state within Shobu until it was needed again.
After the dangerous battles had come by, Shobu and his friends starts to enjoy dueling again. However, the new disturbance began to stir as the original Duel Master, Adam awakens and attempts to drown the world under the ocean. Shobu manages to put the stop to this apocalypse, awakening as the true Duel Master and saving the world with the hopes of humanity and creature spirits. The Proof was then used again, permanently relieving Shobu from being its carrier, conducting its final act by spreading the rest of its power to the world, reviving Shobu's friends from the conflict and somehow allowing Shobu's younger brother Katta to awaken from his vegetative state. Shobu attempts to reunite with his friends but was caught in the blast during the destruction of the tower and drowned into the ocean. This left him to be assumed dead and the world mourned on the True Duel Master's sacrifice.
In truth, Shobu managed to survived but suffers amnesia, losing memories of himself and dueling. He was eventually left wandering around the world for more than a decade, nothing but a husk of his former self.
Katta Kirifuda's Era
Years after Shobu's sacrifice, a bronze statue of Shobu was built and erected onto a park to commemorate the true Duel Master. Shobu's younger brother Katta Kirifuda despises him at first due to being compared to him by others and his sacrifice. This viewpoint was changed when Katta was determined to win against his rival Dragon Ryu. His choice eventually set him down a similar path as his brother, not only dueling in conventional times and also being caught into conflicts relating to the creature world.
Katta's greatest challenge began during his time in middle school. He manages to reunite with his missing elder brother, who had just regained his memories and purpose. After both part ways, Katta continues to the path he believes in while Shobu watches over Katta under the shadows, observing the events of the world.
The final enemy Basara and Dormageddon X, Forbidden Armageddon went to destroy the whole world, Katta Kirifuda and the creature spirits put the end to the ambitions in space. Though he won, it was not without a heavy cost as Katta lost all of his powers to understand creature spirits. He eventually went to the creature world together with his childhood friend Lulu Takigawa and some of his creature friends. During his time in the creature world, he and Lulu fell in love and bore a son Joe Kirifuda.
During the 7 year time gap after Dormageddon X's defeat, Shobu's life status officially changed and he no longer hides away from the world. Shobu makes up for the lost time by spending time and making amends with his family, especially towards his brother and nephew. Katta returns to the human world with his wife and son, and the wedding was raised in front of his family and friends.
Joe Kirifuda's Era
More than 20 years after the events of Shobu's journey, the title of Duel Master was brought up again. Deckie, an animated deck box went to the human world in order to find a Duel Master, in which he was picked up by Joe Kirifuda. At the same time, the balance in the creature world is starting to crumble.
Unlike a duel master in shobu's era, a Duel Master in Joe's era is an enforcer of the balance of the creature world instead of simply a very powerful duelist. It also has nothing to do with the Duel Masters Proof and are simply handed over by the most powerful creatures of the creature world for the people they feel that have the potential to be one, with some of them including Deckie for Joe and Bad Brand for Boltz.
Their job includes hunting for Duel Warriors, creature spirits who appeared in the human world, and either kill them or send them back to the creature world, as well as enforcing against renegade duelists. They also can induce "true duels" who are capable to doing physical harm against the people who participate in them, but so far due to the merciful attitudes of the duel masters Joe Kirifuda and Boltz, nobody were killed.
Duel Masters are capable of awakening their own Master Card, like how Duel Masters are capable of using the powers of their Awakening Cards. However, their awakening varies for each master.
List of Duel Masters
Shobu Kirifuda's Era
The Duel Master of three years prior to the Fighting Edge series. Yaesar lived on The Island at the same time the Fua Family had established their fort there and was Zakira's master. When he was 102, he divided the Duel Master's Proof among seven children after Shori's loss to Zakira.
A Duel Master living in the Southern Pacific Islands. At the time of his debut, he was the youngest Duel Master, but is now second to George in that regard. Toy is an incredibly powerful player, as even before he became a Duel Master, he wielded enough strength to split an island in half during his Duel of Truth with Zakira. His ace card is Death Phoenix, Avatar of Doom. He was able to escape Zakira's capture and Jed's grip, escaping with Esmeralda and Horus.
A Duel Master from Spain. Three years prior, during the Fua Family's invasion, she was saved by Shori Kirifuda but lost her legs in the process, resulting in the use of artificial legs. Up until the end of FE, she used a wheelchair, but after the final duel, Dr. Root transplanted her real legs onto her body. After Richie's defeat, she traveled with Shobu to Egypt. In Egypt, they invaded Toto's fortress and she was found by a robot and escaped, only to do battle with Zakira. Although she was able to hold her own against him using Ultimate Galaxy Universe, she still lost and was captured by Zakira. Because she usually wears glasses and a hat she is seen as unattractive, but beneath it all lies a truly beautiful person. Despite not conveying her feelings, she loves Shobu.
The Duel Master of Egypt. Until volume 6, Horus was nothing more than a cowardly but kind person. Before his duel against Jedd in Paradise, and it was at this time he awakened into his Duel Master abilities due to his enraged soul. He won the duel, but upon putting down his cards he reverted to his former self. His ace card is Supernova Venus la Saint Mother. In the anime, he is seen using Last Avatar and Dolboran against Kokujo.
He is a member of Junior Duelist Center who lives in the southern hemisphere and he have a companion pet which he takes care of Southern Cross.
He is a southern polar bear and is used to be a pet and a precious friend of Sky who was a member of Junior Duelist Center and had a legendary card Bell Hell De Gaul, Footprint of the Reaper.
He is a Duel Master from India and warns Shobu about the danger of Heavy Death Metal. He also escapes from his homeland before the Fua Duelists assault.
He is a Duel Master from America. He was living and playing in the United States but was persuaded to go to Japan by Fua Yu. He witnessed the decisive match between Shobu and Zakira.
George is an older duelist who is short and wears a pink bear suit as well as a pacifier. He rides around in a motor baby carriage.
Joe Kirifuda's Era
Katta's son, Shobu's nephew and Shori's grandson. Joe was born and raised in the creature world in the first 3 years of his life, befriending his father's creature friends since birth. He was brought to the human world by his parents and Dragon Ryu, growing up as a normal boy. He has a passion of drawing, having drawn numerous creature designs and uses Deckie to convert his creations into live creatures.
Joe's childhood friend and user of the Metallica race under the Light Civilization. However, he seems to be manipulated by his mother who has taught him a twisted sense of justice.
A friend of Joe and a wandering duelist who goes around and duels opponents with chilling victory rates with his Beat Jockey rushes. He has a Dachiccoo Churis creature spirit who helps him in his adventures, and he recently made a pact with Bad Brand in order to defeat Kira in a revenge match.