Seto Kaiba, more often known simply as Kaiba, is an on-and-off antagonist in the Yu-Gi-Oh! It implies that despite his willingness to work with Yugi for Mokuba's sake and sometimes his own, the Pharaoh is still ultimately his enemy and one that must be defeated. The sides of the plane appeared as if they disappeared and the seal rose Kaiba and Alister to the roof of the plane and formed a dome over itself.During the Duel, Kaiba is sent to an illusion of a city that was made a battlefield by KaibaCorp, when Kaiba in the war struck city, playing an improvised game of Outside the plane, Kaiba and Mokuba met Joey, Téa, Tristan and Yami, who had followed the dragons.
Kaiba grew suspicious of Zigfried, who had entered the tournament under the name "Zigfried Lloyd", when he saw him announce to a surveillance camera that he has a special show in store for Kaiba, before Dueling Kaiba prepared for an attack on the computer system, such that he would be able to completely back-up the system should it get damaged.During Joey's Duel with Zigfried, Zigfried thought Kaiba was too slow with figuring him out and gave Kaiba a clue by triggering a virus causing electronics around the park to go haywire. Kaiba then remembered his encounter with Zigfried at the party thrown by Gozaburo.They found no personal or family information about Zigfried Lloyd, but plenty of tournament history and that he had entered these tournaments through the recommendation of politicians who were not available to comment. She bade him farewell and ran off.Kaiba followed Kisara and watched her warn Priest Seto of the danger. Kaiba was surprised to hear that Yugi still thought he could win. Kaiba hid on one of the walls and listened-in on a group of Pegasus' guards, who had been unable to find him.

When the orphan Seto got adopted by Gozaburo Kaiba, he was strictly taught the ways of technology and company business day after day, and Gozaburo was cruel to him. However they were ambushed by Kaiba and Mokuba stopped at a car shop and hopped into After the Duel, the building started to collapse. They quickly Summoned "Kaiba thought Battle City was his tournament, the entire event was designed so that he would be victorious, he wanted to put the memory of his adoptive father behind him and be crowned the world's best Duelist atop his As Kaiba left, Joey, who had awoken from his coma, challenged Kaiba to a third place play-off. Many plot elements are also influenced by Egypt and Egyptian mythology, and as such, Egyptian characters also appear within the story. Yugi handed Kaiba and Joey back their Legendary Dragon cards and the trio entered a vortex transporting them to the heart of Atlantis. However Kaiba picked As they Dueled, Zigfried stated how KaibaCorp had always been one step ahead of Schroeder Corp in the gaming industry, including Kaiba making the contract with Pegasus to develop holographic technology for As Leon faced Yugi in the title Duel, Kaiba noticed Leon was acting strange. Unable to live with the defeat, Gozaburo committed suicide,After taking control of KaibaCorp, Seto shifted its economic interest from manufacturing weapons of mass destruction to game-oriented equipment. At various points during the series, he opens up momentarily, performing kind acts, though always covering them up with sarcasm, and denying them if asked. Seto asked Noah why he's making them watch this stuff.
Noah insisted that it was Kaiba's former employee that kidnapped Mokuba and that he was the one who rescued him.

His pride in himself and his accomplishments as an individual are prominent character traits that form a part of his character throughout the series, and he reacts harshly to those who threaten or infringe on it (although it is toned down slightly towards the end of the series).