Priest Seto

Seto is a priest who is a cousin of Pharaoh Atem. Seto Kaiba is the reincarnation of Priest Seto. Seto is named after the Egyptian God Set.

Anime and Manga
3000 years before the present day events of the anime and manga (5000 in the English anime), Priest Seto and Pharaoh Atem (the past incarnation of Yugi Mutou) were friends and rivals who helped each other by testing their skills. Although technically Atem's cousin by blood, Seto is raised as a commoner; his identity as Priest Akhenaden's son (who is the brother of Atem's deceased father, Pharaoh Akhenamkhanen) is hidden from him out of fear for his personal safety. He is eventually able to become a part of the Pharaoh's court not because of his lineage, but because of his test scores, which are the highest the court has ever seen. This high degree of intelligence has apparently carried over to his modern reincarnation.

When Bakura - the arc's main antagonist - appears at the royal court with his powerful Ka Diabound, Seto decides that Bakura needs to be stopped and begins his search for Ka powerful enough to defeat Diabound. People could be tortured into revealing their Ka, so he decides to try rounding up and torturing criminals. This plan, he believes, would accomplish two things: both finding a Ka that could destroy Diabound and reducing the number of criminals that ravage the Pharaoh's kingdom. During his search, he encounters Kisara, who is being stoned because of her unorthodox complexion (white hair, pale skin, blue eyes). Shada senses the great power within her ("even surpassing that of the gods") and Seto takes her back with him to the palace. There he remembers the first time they met: as children, Seto had saved Kisara from slave traders, who had kidnapped her from her home country and were planning to sell her for a high price. She repaid him by unconsciously releasing her Ka--the Blue Eyes White Dragon--after the traders set fire to his village and killed his mother in retaliation.

Akhenaden, after being possessed by Zorc, later attempts to test Kisara's power by forcing her to fight in a battle against two other prisoners. Seto steps in and saves her, but the two fell into danger, causing Kisara--out of fear for Seto--to release her dragon and save them both.

Akhenaden then orders Seto to kill Kisara and extract her Ka, claiming that the power of the white dragon can surpass the enemy and even the Pharaoh's three gods. If Seto can obtain it, Seto can become the new king. Seto refuses, and Akhenaden kidnaps him in an attempt to corrupt his mind with darkness. At this point Akhenaden reveals that he is in fact Seto's father, and that his lifelong desire has been to see Seto ascend to the throne.

Before Seto can decide, however, Kisara runs to save him, ultimately convincing him to leave Akhenaden/Zorc behind. Enraged, Akhenaden questions how his son can abandon the chance to rule over Egypt. Seto answers: "What is there to benefit from a world of darkness ruled by Zorc? Since I met Kisara, I realized how much of the world was dark and dry. And the solution to make this darkness disappear is through this light called love." (YGO, Episode 214) At this point Akhenaden fires off a beam of dark energy, and Kisara dies taking the blow meant for Seto.

After Kisara's death, Seto attempts to kill his father, but instead his mind is taken over by Akhenaden/Zorc and he is forced to duel Pharaoh Atem. Kisara saves Seto once more by using her "light" to purge Akhenaden from his mind, making Seto the new keeper of the Blue Eyes White Dragon. Seto sheds his first and only tears in front of the BEWD tablet, with Kisara's dead body in his arms. Notably, this is the "vision" which appears to Kaiba during his duel with Isis Ishtar in Battle City.

Subsequently, Seto fights bravely by Atem's side in the battle against Zorc Necrophades using the BEWD. When Zorc is defeated, Atem tells the priest his reign is over, and passes the throne onto Seto. Seto then creates the famous stone carving of the two of them, as a tribute to his friendship with Pharaoh Atem.

It is hinted that Kisara's deep bond with Priest Seto is the reason behind Kaiba's modern-day fixation with the Blue Eyes White Dragon.

In the Yu-Gi-Oh! GX manga, Seto makes a possible appearance as a figure in the past of Tragoedia and appears (along with Aknadin and Karim) to have been responsible for sealing him.

Yu-Gi-Oh! Forbidden Memories
In Yu-Gi-Oh! Forbidden Memories, Seto is portrayed more as an antagonist. He is the high mage Heishin's right hand man and rival to the prince (Atem, although the player names him).

He first appears dueling and defeating Jono. He mocks Jono's dueling skills, but Jono tells him that he isn't good enough to beat Atem. Seto cannot duel as he is called to meet Heishin, but agrees to duel Atem later. Seto later arrives at the Dueling Grounds, to face Atem. After Atem defeats him, he recognizes him as the Prince. None of Atem's friends had been aware of this.

After the Mages, take over, Seto finds Atem at the Forbidden Ruins. He explains the meaning of the map Atem has, that it gives the location of each Millennium Item. He advises Atem to defeat each High Mage at each of the shrines on the map. Sadin advises Atem not to trust Seto. Regardless, Atem follows Seto's orders.

After Atem defeats one of the High Mages, Seto kidnaps Teana and holds her hostage to draw Atem to him. Jono and Atem arrive at the Dark Shrine to rescue her. Heishin orders Seto to defeat Atem and take the Millennium Puzzle as his prize for winning. Seto drags Teana into a secret room, where he duels Atem. After Seto loses he gloats about the Mages don't stand a chance against Atem.

After Atem defeats the remaining High Mages and takes their Millennium Items, Seto approaches him and tells him to go to the now unguarded Dark Shrine, where he can face Heishin. Atem complies and meets Seto at the Dark Shrine. Here Seto shows him the way to Heishin. After Heishin loses, Seto takes Atem to the ruins. Here he reveals his true plan. He had gotten Atem to gather all the Millennium Items and take them to the Forbidden Ruins. Now Seto could use them to aquire great power, by summoning DarkNite, but Heishin appears and holds a knife to Seto's neck demanding the Items from Atem or he would kill Seto. Atem gives Heishin the Items, which Heishin uses to summon DarkNite.

After Atem defeats DarkNite, Seto disappears and is never heard from, within the kingdom, again. Pri

Deck/Monster Spirits
In the anime and manga Seto Summons the following Monster spirits:
 * La Jinn the Mystical Genie of the Lamp (As seen in the flashback from Ishizu's Millennium Necklace)
 * Battle Ox
 * Blue-Eyes White Dragon
 * Duos
 * Duos Dragon
 * Garestgolath
 * Mystic Horseman
 * Rabid Horseman
 * Winged Kuriboh

In Yu-Gi-Oh! Forbidden Memories, the first time the player (Atem) faces Seto, his Deck contains many strong cards for such an early stage in the game, like "Gaia the Fierce Knight" and "Ushi Oni". The second time he's faced, he now uses "Blue-eyes White Dragons". The third time faced, Seto uses many powerful cards like 3 copies of "Blue-eyes Ultimate Dragon".