Sartorius, known as Takuma Saiou (斎王琢磨 Saiō Takuma?) in the original Japanese language version, is a fictional character in the Yu-Gi-Oh! GX anime series. His name is meant to be a pun in English, as "satori" denotes a "spiritual awakening". In the English version, Sartorius is voiced by the late Maddie Blaustein, while Takehito Koyasu (older) and Mayumi Yusa (younger) take the role in the Japanese version.
A fortune-teller with dual personalities under the influence of an alien force, Sartorius serves as the main antagonist of the series' second season, poised to remake the world in the image most befitting the extraterrestrial radiance within him.
Sartorius' character design was overseen by Kenichi Hara. His usual outfit consists of the standard Obelisk Blue uniform with a raised and buckled collar and matching cut-offs for his arms and legs. A deck box is strapped to his right leg, presumably to house his regular tarot deck. His blue hair is sectioned in two layers, the layer closest to his face a lighter shade of blue than the one behind it, which generally flows as a single unit. Directly above his nose is another section of hair, colored greyish white, and he also wears earrings and a pair of ornaments on either side of his forehead. He carries an Academy-issued Duel Disk on his left hand despite his initial preference of dueling on a table.
His natural complexion is flesh-tone, however, with his evil personality in dominance, his skin takes on a more pallid quality. Furthermore, his eyes are more sinister and glazed over by light. When completely corrupted by the Light of Destruction, his hair becomes wild, his face inhumanely twisted, and his teeth elongated.
In the timeline of the Yu-Gi-Oh! GX anime, Sartorius and his sister Sarina were shunned and humiliated by others out of fear of their abilities to tell the future as children, and driven to run away from home. The siblings shared a close relationship which extended into adolescence, and Sartorius searched for hope of escaping his ruinous destiny in a young Aster Phoenix. This depth of this relationship has been revealed on both sides throughout the plot: during the dominance of Sartorius' evil personality, Sarina willingly sacrificed herself in order to ensure help Jaden restore Sartorius' old personality. Similarly, in the assault of darkness in the fourth arc, Sartorius sacrifices himself when Sarina is held hostage by darkness. Fearing the corrupt "Ultimate Destiny Card," the to-be-Pro League king The D sought the kind and caring Sartorius for guidance, but accidentally imbued him with the will of a dangerous alien energy known as the "Light of Destruction," which had taken up residence in the card. This provoked (like it had in The D) an onset of dissociative identity disorder, forcing Sartorius to contend with a dominant evil persona. The card would disappear from his possession shortly thereafter.
Sartorius formed a cult, the Society of Light, to worship the Light of Destruction, and keeping close ties with Aster, he became Aster's manager. On the surface, Sartorius and his organization aimed towards world domination starting with Duel Academy via expansion of their syndicate, but the man's gravest concerns lied in putting his stalled Wheel of Fate (a metaphor for his fate) back into motion through the powers of Jaden Yuki and Aster as means of overcoming his destructive future. Although this goal was always on his mind, he was pushed towards an ultimate motive of eradicating the "age of darkness" that had befallen the planet by blanketing the globe in light. In the English version, he planned to control the minds of the Earth's inhabitants, making them forget about things like corruption, greed and violence, while in the Japanese version he planned to destroy the Earth instead, killing all its inhabitants to restore balance to its imperfect state. Only then could the world (or on a greater scale, the universe) be created anew. Sartorius would himself be placed in Obelisk Blue as a first-year (third-year in the Japanese version) transfer student.
Sartorius selects Prince Ojin as his first opponent in the GX tournament, wishing to obtain the satellite technology of the prince's country. Although Ojin nearly defeats Sartorius on his first turn, Sartorius defeats Ojin before he even takes his first turn, claiming the control keys to the satellite. In order to prevent his evil side from instigating his plans, Sartorius approaches Jaden and Aster, giving them the keys. He is eventually sought by Aster, who breaks into Obelisk Blue to find him in the Society of Light's private duel field. As Aster is about to give Sartorius his key to the satellite, Jaden intervenes and tells him its true purpose, prompting the boy to wager it in a Duel instead. Recognizing the present Sartorius as an impostor posing as his lost companion, he struggles against the Arcana Force monsters, who deny him control over his fate by stopping their own rotations in their master's favor. Although Aster makes a comeback with timely help from Sartorius' good-hearted alter ego, the Light of Destruction unleashes Arcana Force Extra - The Light Ruler to end the duel.
Afterwards, Sartorius and Jaden face one another to determine the fate of the world. Similar to the preceding match with Aster, the diviner's cards continue to stop their own rotations. Having obtained both keys due to a blunder on Jaden's part, Sartorius sends Ojin to arm the satellite while he keeps the boy distracted. With the combined efforts of Elemental Hero Neos, Tyranno, and the returning Sarina, the weapon is dispatched, and Jaden defeats Sartorius, sealing away the Light of Destruction. Finally free from his fate of ruin and the burden of seeing into the future, Sartorius thanks both Jaden and Aster for their kindness, and is reunited with his sister. The two are then transported to a KaibaCorp hospital to recuperate.
Sartorius wields supernatural powers, including the ability to insinuate his spiritual energy into inanimate objects (as he did with Aster's deck), as well as other people. He can also temporarily render others motionless either from a distance or with a single touch. His primary power, however, is seeing into the future with the aid of his tarot deck, a divination technique he shares with his sister, though she instead uses mirrors to channel her powers. He is also a master manipulator, able to say exactly what is needed to be said to get anyone he or his associates in the Society comes into contact with to do his bidding.
In the English version, Sartorius' voice is reminiscent of a young Hannibal Lecter, while his original series counterpart occasionally replaces certain Japanese words with anglicisms, the most common being his substitution of the words "shōkan" (召喚) and "hatsudō" (発動) with "play," an English equivalent to both "summon" and "activate," respectively.
In Season 4, along with Kagemaru, he receives a premonition of the coming danger of Darkness, and proceeds to warn Jaden. However, during this period, he succumbs to the darkness in his own heart, adopting the philosophy that in order to protect those important to you, you have to obtain extraordinary power, and to do so, evil is necessary. It is also revealed that Sarina was captured in some way or form by Nightshroud, and Sartorius was forced to aid Darkness in order to retrieve her. This appears to be quite similar to Jaden's decent into evil as Supreme King during the third arc. However, unlike Jaden, Sartorius did not go all the way, and maintained respect for Jaden and other duelists opposing him.
Sartorius was assigned the task of eliminating Jaden Yuki from the playing board, and should he fail to defeat Jaden, something would happen to Sarina. The exact threat was not disclosed. Sartorius at first deceives Jaden by rescuing him from a Austin O'Brien clones (whom Trueman copied after defeating the latter), but reveals his true intentions when he drives Jaden to helicopter port in his motorcycle and not arranging for a helicopter to appear to take them to Duel Academy. Sartorius then reveals that bombs have been set to go off when one of the two attempts to leave the building, thus trapping them in and forcing them to duel, the loser being consumed by Darkness. This event set up further reflects Sartorius' continuation of his obsession with destiny: both of their bodies' destinies were now imprisoned within the building. After losing the duel, Sarina's spirit (it is not explained why it appears) comes to escort Sartorius into the dimension of Darkness, and Sartorius, now at peace, wishes Jaden luck in escaping the building alive. He and his sister both re-appear after Jaden defeats Nightshroud.
Sartorius plays a Tarot deck, composed largely of Arcana Force monsters based on the Major Arcana, with Spells and Traps based on the Minor Arcana. His cards have the unique ability to appear in either upright (normal) or reversed (upside-down) positions, which dictates their effects. When activated, Sartorius' cards rotate, and it is up to the opponent to decide when to end the rotation, in turn deciding his/her own fate. The design of cards in the Arcana Force series has links to the Cthulhu Mythos. In the original version of the series, although the rotation of most of Saiou's cards determines their effects on-screen, the Japanese text on the cards themselves lists their abilities to be coin toss-activated.
To compensate for the excess of high-level monsters in his deck, Sartorius has a variety of ways to bypass negative repercussions. One of his most effective strategies involves Arcana Force III - The Empress and Arcana Force XVIII - The Moon, both of which provide him with an accelerated output of sacrifice fodder for such cards as his Arcana Force XXI - The World. While this may appear to be his most powerful card, capable of forcing opponents to skip entire turns, his greatest monster is in fact Arcana Force Extra - The Light Ruler, which is heralded by the "Three Pillars," a convergence of red, blue, and green columns of light. The Three Pillars reference the legend of the Tower of Hanoi, which states that the world will end given the completion of said puzzle. When mixed evenly, the aforementioned colors within the visible spectrum also form white light.
During his duel with Jaden in the fourth season while under the influence of Darkness, Sartorius utilizes a new strategy reflecting his changed philosophy on destiny revolving around the combination of "Arcana Force Zero- The Fool", "Grim Reaper's Tour/ Death's Tour" and "Planting of the Fool". Through the Fool's effect, Sartorius can now choose which of his card's effects to activate without trusting to chance. Through this he can now safely use the effect of "Grim Reaper's Tour", which has an equal chance of preventing either player from summoning a monster during their turn, to shut out his opponent's ability to summon monsters entirely. In addition, and a little pute Planting of the Fool allows Sartorius the ability to discard cards from his opponent's deck. The use of "The Fool" in his duel with Jaden is significant because it is revealed during season two that Jaden's actions in Sartorius's predictions are determined by the Major Arcana card "The Fool".