|It has been suggested that this article be split into multiple articles accessible from a disambiguation page.|
First series anime only characters
The Four Game Masters
The Four Game Masters, consisting of Ridley Sheldon, Ryuichi Fuha, Aileen Rao and Daimon are a group of gamers who appear only in the first series anime, with the exception of Daimon. They were hired by Seto Kaiba to defeat Yugi.
Student Council Chairman
Second series anime only characters
Aaron, known in Japan as Juan was Alister's best friend growing up. Seto encountered him and two other boys when Alister showed Seto a vision of his past using the power of the Orichalcos. Kaiba decided to go outside his hiding place with the boy and plays chess with him. He is later killed in an explosion by a group of Kaiba Corp tanks (in the dub, he sees an explosion has happened near where the other boys were. He tries to go to them but Kaiba holds him back saying it's to dangerous. Aaron keeps pleading, but when Aaron looks back at Kaiba, Kaiba sees his own brother, Mokuba, pleading with him. Suddenly, tanks come and Alister appears and Aaron disappears). He is voiced by Sebastian Arcelus in the dub.
Once King of Atlantis brainwashed by the Orichalcos and told to revive The Great Leviathan
The Great Leviathan (known as Orichalcos God in the Japanese version) was a ancient dragon god that intended to destroy the world. He created the orichalcos stones getting the name the orichalcos god. He employed the Orichalcos stones to corrupt people. he and his followers destroyed Atlantis but the Great Leviathan was weakened and lied dormant in the ocean. Dartz gathered souls to revive him. Near the end of season 4 Dartz succeeds in awakening the Great Leviathan and merges with him. He battles Yami Yugi, Seto Kaiba, and Joey Wheeler but they defeat him. He lingers on in spirit form inside Dartz and attempts to turn Yami Yugi's darkness against him but Yami Yugi conquers his darkness. In the English dub Yami Yugi proceeds to seal away the Great Leviathan. In the Japanese dub Yami Yugi purges the darkness out of the Great Leviathan and it goes on to live in Duel Monsters Spirit World.
KC DuelTek 760
Monsters that were created by The Great Leviathan to help Dartz feed souls to ressurect the ancient serpent god.
KaibaCorp Grand Championship Contestants
The contestants, who only appeared in the KaibaCorp Grand Championship. These included: Abe the Monkey Man, Balfry Ginger, Ethan Shark, Richard Goat, Jafar Shin, Fortune Salim, Paul McGregor, Sergei Ivanoff, Shane Jordan, Totani Ialos and Vivian Wong.
Seto Kaiba's step brother.
Leon von Schroeder
Zigfried von Schroeder
Manga only characters
Junky Scorpion store owner
Old Man Dentures
Capsule Monsters only characters
Dr. Alex Brisbane is a direct descendant of Alexander the Great. He was working with Dr. Solomon Muto in India exploring a mysterious pyramid. They entered it and only Brisbane got out, Dr. Muto apparently disappeared in to thin air. Later, when Yugi and friends came, he led them to the chamber in the pyramid where Dr. Muto disappeared. It turns out that when professor Brisbane entered, he got possessed by the dark side of Alexander the Great and used Yugi and his friends to unleash the "ultimate power." He is voiced by Pete Zarustica in the dub.
One of the greatest conqueror in history, Alexander the Great was an ancient king who nearly conquered the world, and serves as the main villain during the Capsule Monsters mini-arc. Through his armies some of the ancient world's greatest nations fell before him, including Greece, Persia, and Egypt (the latter of which made Alexander into one of the great pharaohs). During his adventures Alexander came into possession of the Millennium Ring and began to carry it as a lucky charm. However, the ring soon began to cloud his mind, causing him to turn power-hungry and losing the respect of his troops (except for a handful of his servants). Wanting ultimate power Alexander was confronted by Shadi who told him to take the trial of the Capsule Monsters if he wanted the power. Alexander passed the trials, but was not allowed the power he wanted and his soul was trapped within the legendary Pyramid of Alexander (located in India). His spirit was also torn in two, one good (which was trapped within the game) and one evil (this one being trapped within the temple). Alexander's evil half would later possess his direct descendant.
After Yugi and friends passed the Capsule Monster trial (with the help of Alexander's good side), they crossed back into the pyramid and confronted Alexander's possessed descendant. He managed to steal an artifact that would allow him to unlock an ultimate power from within the temple. However, he was foiled by Yugi and friends and Alexander's dark half was banished forever, while his good side's spirit finally passed on to rest.