Time travel is a person or object's movement away from the present time and to a different point in time in the past or the future. It is used by multiple characters in the series, particularly various incarnations of Xehanort in order to fulfill their purposes of starting the Second Keyblade War.
- 1 Overview
- 2 Known Time Travelers
For someone to move through time, they must first abandon their body, becoming nothing more than a disembodied Heart in the process. Xehanort accomplished this task by turning himself into a Heartless, allowing this incarnation of the man to make the travel necessary to begin the recruitment of the Thirteen Seekers of Darkness.
The act of disembodying one's heart also allows the traveller to grant access to time travel to incarnations of themselves scattered through different points of time. However, so long as these incarnations are not disembodied, they are unable to travel through time of their own accord, requiring assistance from the disembodied traveller.
A unique method for time travelling was the doorway to Timeless River, which did not abide by the normal rules of time travel.
In order for one to travel to a certain point in time, there must be another version of them waiting at said destination. In addition, rewriting the events that are destined to happen is forbidden in the laws of time; what is set in stone cannot be changed. Upon return to one's original point in time, the traveler loses all memory of the experience gained traveling. In spite of this, the memories of these experiences are etched into the traveler's heart, which can potentially have an effect on their perspectives and decisions.
However, Sora was able to alter the events that were originally destined to happen, thanks to his interaction with a Chirithy present in The Final World prior to travelling back in time, successfully altering time and saving the Seven Guardians of Light.
The doorway to Timeless River does not follow these laws.
Known Time Travelers
Realm of Light
With the ability to travel through time granted to him by Ansem, Young Xehanort uses his newfound power to visit dispersed versions and vessels of himself in many points in time. Able to gather ten of these individuals, he gathers them in the present day to join Xehanort's Thirteen Seekers of Darkness. The only incarnations having been collected since the Past were Young Xehanort himself, Xemnas, Ansem, Vanitas, Terra-Xehanort, and later, Dark Riku. In addition to this, when placed on Destiny Islands by Ansem during a time before it was destroyed by the Heartless, he is able to follow Sora and Riku into the Realm of Sleep. With Sora marked by the Recusant's Sigil and Young Xehanort present in the same time period as him, the youngest incarnation of Xehanort is able to keep tabs on him wherever he might be. This allows him to track Sora wherever he goes as part of his assigned task to turn him into the thirteenth vessel for the Thirteen Seekers of Darkness.
Terra-Xehanort is the body of Keyblade apprentice Terra possessed by the heart of Master Xehanort. During his apprenticeship under Ansem the Wise, he takes the opportunity provided by Ansem's trust and resources to further study the Darkness and find potential ways to gain further access to its powers. Upon banishing Ansem to the Realm of Nothingness, he takes his former master's name and falsely assumes his identity, then proceeding to separate his heart from his body, splitting himself into a Heartless and a Nobody: Ansem, Seeker of Darkness, and Xemnas, the leader of Organization XIII. At some point before being split into Ansem and Xemnas, his heart was collected by Young Xehanort so he could be made one of the Thirteen Seekers of Darkness in the future.
Ansem, Seeker of Darkness
Ansem's function as a Heartless, a disembodied heart corrupted by darkness, enabled him to travel through time, just as Xehanort planned when he cast off his heart to create the former incarnation. Using this ability, he travels to the past and arrives on his original self's former home world, Destiny Islands, to convene with a younger version of himself. With time travel powers granted to him and the rest of his incarnations by Ansem, Young Xehanort is able to travel through time without leaving his body behind. His task fulfilled, Ansem returns to his own time and places himself on Destiny Islands, where he places the Recusant's Sigil on a time travelling Sora.
Ansem later possesses Riku, reshaping Riku's body into a physical form designed in his image. Even after his initial defeat he remained within Riku for an extended period of time. At some point prior to his final defeat, his heart was collected by Young Xehanort so he could be made one of the Thirteen Seekers of Darkness.
Following her defeat in Kingdom Hearts, Maleficent took advantage of lacking a body, and with the information on time travel she had been given by Xehanort she traveled back to the events of Kingdom Hearts χ. Unfortunately, she discovered that no matter what changes she made to the past, it would have no bearing on the future.
Like many other Seekers of Darkness, Dark Riku had traveled from the past to the present in heart form to use a replica created by Vexen as a vessel. We first see Dark Riku make a short appearance in Prankster's Paradise, more precisely in Monstro, which seems logical since the real Riku had already found there at the time. We will first think that it was the real Riku of the time when Ansem, Seeker of Darkness, had taken possession of his body. But in reality, it was Riku Replica of the time Naminé had been forced to remake his memory on behalf of Marluxia and Larxene.
Being a Nobody, Xemnas is not supposed to be able to travel in time, that's why he stayed in the present to found Organization XIII. Nevertheless, since Nobodies are able to gain replacement hearts, Young Xehanort was able to collect Xemnas' heart (from at some point prior to him merging with Kingdom Hearts) on his travels to have him join the Thirteen Seekers of Darkness.
Having lost a body following his battle with Ventus, the fractured heart of Vanitas became capable of time travel. He was collected by Young Xehanort at some point between the events of Birth By Sleep and Dream Drop Distance to be made one of the Thirteen Seekers of Darkness, though he was one of the last to be given a Replica body.
Sora and Kairi
Ending up in The Final World following his and the other guardians' deaths due to Terra-Xehanort and the massive Demon Tide, Sora and Kairi traveled back together to before the battle to change the events.
Realm of Sleep
Sora really got the power to travel in time after sacrificing his heart to give back to Kairi. That is why he was able to return to the Destiny Islands before they were engulfed by the Heartless during his Mark of Mastery Exam, even if the rules of Time Travel are much more flexible in the Realm of Sleep than in the Realm of Light.
Riku got the power to travel back in time after Ansem, Seeker of Darkness, took possession of his body, which sentenced Riku's heart to travel to the Realm of Darkness. That is why he was able to return to the Destiny Islands before they were engulfed by the Heartless during his Mark of Mastery Exam, even if the rules of Time Travel are much more flexible in the Realm of Sleep than in the Realm of Light.
Ursula appears as a Giant at the moment when Sora and Riku left the Destiny Islands to begin their Mark of Mastery Exam, and though she herself doesn't mention it precisely, she would not have succeeded without the help of Ansem, Seeker of Darkness, who was on the Destiny Islands, at the moment when they were engulfed by the Heartless.
In the Realm of Sleep, Sora and Riku will each meet a Mickey Mouse from the Past in two different sleeping Worlds: the Country of the Musketeers and the Symphony of Sorcery. Which may seem paradoxical, since Mickey was not supposed to have any experience in Time Travel at the time of the series.