Prior to debut
When he finds Akiza for the first time, he welcomes her into the Arcadia Movement, a group of people with powers similar to hers. Sayer is the leader of this group of duelists training to control and harness their psychic abilities. He has plans for her to be a member and a representative figure of the organization.
Sayer finds Toby Tredwell, who also has Psychic Dueling powers and takes him to the Arcadia Movement to test his abilities. Toby was unable to withstand the procedure. Believing him to be weak and useless, Sayer ordered the intensity of the electric shocks to be amplified, which caused the young boy's death. (In English version, Toby was taken into a another location under Sayer's orders.)
Sayer, as he appeared during the Fortune Cup arcSayer watches over Akiza's Duels in the Fortune Cup and encourages her to be proud of her powers. He also does his best to keep Akiza secluded from anyone outside the Arcadia Movement, including Lazar and Yusei - possibly because he does not yet trust In the dub, before her duel with Yusei, however, he reveals his motive. He claims that "He Who Rules The Sky" - possibly ZONE - has given the Arcadia Movement the mission of stopping Yliaster from resurrecting the Crimson Dragon, and stopping it from "bringing the world to its knees".
When she loses to Yusei, he leads her out of the arena to recover from her defeat before Yusei has a chance to speak to her. However, Sayer returns to watch the final match to see if the Crimson Dragon will appear. During this duel, his earlier belief of his God-given mission seems to be forgotten; he merely comments that it will be interesting to watch.
Later he received a message from Bolt Tanner, who requests that Sayer help the Signers against the Dark Signers. Luna, Leo, Yanagi and Tanner go to the Arcadia Movement to attempt to unite all of the Signers against the Dark Signers, however, even after explaining the current situation to Sayer it appears he already has other plans. As he and other members sedate them with a gas, Sayer wants to make Luna a member of the organization because of her power, having been planning it for some time prior to the meeting.
When the gas wears off, Sayer has chained Leo in his Duel arena to personally test him for any Psychic power while Luna and Akiza watch from the observation room. Before the Duel begins, Sayer explains that the Arcadia Movement has no interest in dealing with the Dark Signers and that he wants to use Luna, along with other psychic duelists, as soldiers to start a war against the world. Since Leo is Luna's twin, he might have special abilities of his own.
To add to the pressure to unlock any potential psychic power in Leo, he threatens Leo's life because he revealed his true intentions before the Duel begins. As the Duel commences, Sayer inflicts some damage on him. Leo fights back by Synchro Summoning "Power Tool Dragon", inflicting major damage to Sayer. However, Sayer emerges victorious as he used an impressive card combo that ended with "Battle Teleportation", allowing him to attack Leo directly with "Thought Ruler Archfiend".
The attack threw Leo hard against the floor and knocks him out. Sayer, accepting that Leo has no special powers, considers him a worthless drag. However after the Duel Sayer assures Akiza that he won't put him through any more harm. Instead he says he plans to use him as a tool to get to Luna.
After his Duel with Leo, he speaks to Akiza about the organization plans of gathering more members from around the world. Also that she will come to represent the Arcadia Movement itself not only as a symbol, but also as a modern "Joan of Arc".
Meanwhile, Carly Carmine sneaks into the Arcadia Movement building and finds Sayer's secret room, which triggers Sayer's psychic sense. He returns to his office and challenges Carly to a Duel with her life on the line. Carly Summons 3 of her "Fortune Fairies" and raises their ATK to 3000. However, Sayer swarms Carly with Psychic monsters and destroys her key card with "Psychokinesis" and pins her to a window with his attacks.
Carly warns Sayer that the Public Security Bureau will investigate her death, but he informs her that her death will be considered an accident by Sector Security. He explains to Carly that he knows Goodwin's weakness, that he was born from Satellite rather than in New Domino City, and because of that he is safe from the Public Safety Bureau. His last attack defeats her, shattering the window she was pinned against and leading her to her apparent death.(This was made less obvious in the English version,in which she falls into a purple fog.)
Carly revives as a Dark Signer and appears again to Sayer in order to challenge him to a Shadow Duel for revenge. He starts the Duel confident that he'll win again, but Carly is able to destroy his first monster and more than half his Life Points with ease on her first turn. Following this, Sayer attempts to make a comeback on his next turn and thinks of a strategy which would allow him to bring out "Thought Ruler Archfiend", but this is futile as Carly, on her next turn, Summons her Earthbound Immortal, Aslla piscu and uses it to defeat Sayer. Sayer's "death".The explosion caused by the attack throws Sayer down the building's stairwell. Akiza sees Sayer falling and cries out for him in shock. (in the english dub, Sayer fell in the same purple fog that Carly fell in.) Afterwards, the Arcadia Movement building begins to collapse after "Aslla piscu's" attack.
Return and actual deathSayer disguised as a security agent.Sayer somehow survived his fall with a scar on the right side of his face hidden by his hair, which also changed to a more rough style. He poses as a security agent from Goodwin and tricks Mina into a water pit, and attacks Yusei, eventually ending up with Mina.
After saving Akiza from landing into a shard of shattered glass, he tells to continue the Duel with Misty. But as Akiza tells him that she can't, Sayer reveals to her that psychic powers were strong even when they were dormant while she was young. He had somehow sealed them without her knowing this.
Sayer releases the seal, unlocking her true powers with the phrase "The entrance to the Underworld is on the witch's island" Akiza's powers awaken and becomes the Black Rose once again. Sayer claims that this power surpasses that of the Dark Signers. While watching the Duel from someplace safe, he states that he and Akiza will resurrect the Arcadia Movement.
Yusei confronts Sayer and asks what he is really here for. Sayer reveals his scar, stating it to be a result of the Dark Signers attack on the Arcadia Movement headquarters. Claiming to have control over Akiza's mind, he says that she only will obey him. Yusei commands him to release Akiza, stating that she has changed. Sayer refuses and attacks Yusei with "Hinotama".
Sayer states that anybody who falls prey to him, will simply follow his orders and nothing more, as he takes full advantage of that individual's weakness, just like he did with Akiza. Although at that time, he acknowledged her incredible psychic powers along with her loneliness.
He explains that Misty became a Dark Signer, because of what happened to Toby. This leads Yusei to figure out that Sayer was involved in Toby's death.
Sayer reveals the truth of Toby's death, prompting Yusei to attack him, but Sayer avoids him and attacks again with "Hinotama". Yusei is left hanging from a balcony, but laughs as he reveals that he had activated his Duel Disk's voice intercom, thus allowing Misty to hear the real story of her brother's death. Sayer gets eaten by Misty Tredwell's "Earthbound Immortal Ccarayhua". Hearing this, Misty believes Sayer is the real culprit for her brother's death. Sayer unwisely tells her that Toby was too weak and that he had no use for him anyway. Fueled by Misty's anger and intent on revenge, Earthbound Immortal Ccarayhua then steps in, snatches Sayer with its tongue and proceeds to devour him, fulfilling Misty's vengeance for Toby. (In the English version, he simply disappears after Ccarayhua takes him.) Unlike everyone else resurrected after the fall of the Earthbound Immortals, Sayer did not.