The White Dragon was Kisara's spirit ka. Kisara's ka and ba were united, meaning the dragon somehow possessed Kisara and was using her as a vessel. It could only emerge, while she was unconscious, which initially left Kisara unaware of its existence.
The dragon was spotted by an exiled criminal, while he was in the desert. He believed it to be a god and that it answered his prayers to get out of the desert alive. In gratitude, he promised to not do anything bad again. He tried telling his story to the barman at the Winking Camel Bar, who believed the heat had gotten to the criminal. He was soon spotted by soldiers led by Seto in his ka hunt. The criminal believed Seto to be abusing his authority and warned him that he would be judged by God, The White Dragon.
During the ka hunt, Seto encountered Kisara, defending her from attacking citizens, who believed her to be a bad omen. As Seto had her taken into his care, Shada's Millennium Key reacted to Kisara's immeasurable heka and showed him The White Dragon ka residing in her. Seto planned on extracting The White Dragon and had Kisara taken to a room in the palace to recover.
Four days later, Kisara woke up and Seto had her taken to the palace underground, where criminals found in the ka hunt had been forced to battle.Gebelk insisted that they test The White Dragon by having Kisara battle the criminals, but Seto was concerned that she might die. However Akhenaden believed Seto was destined to become Pharaoh, after Atem's disappearance, and that he needed a god to do so, so he demanded that The White Dragon be tested.
Kisara put up no resistance against the criminal's ka, so Seto intervened. When Kisara was unconscious and she and Seto were in danger, The White Dragon emerged. It shielded Seto and Kisara with its tail and launched a light-based attack from its mouth, killing the remaining prisoner and Gudoul. The attack burst through the dungeon's ceiling, sending a pillar of light into the sky. After the dragon disappeared, Akhenaden said that Seto must become its vessel, which Gebelk said would be possible by freeing Kisara's soul from her body, but Seto was not happy with the idea of killing her.
During the final battle with Zorc Necrophades, Akhenadin urged Seto to join him and Zorc and rule the new world. He informed him that Kisara would die soon, allowing him to take The White Dragon. Seto refused to join Akhenaden and tried to take Kisara to safety. However Akhenaden killed Kisara and possessed Seto. He used the Millennium Rod to seal The White Dragon in a tablet and forced Seto to battle Atem. Akhenaden got The White Dragon to defeat Atem's Dark Magician, but Kisara's spirit then appeared and turned the White Dragon on Akhedanen, killing him.