Master Xehanort

Xehanort is the main antagonist of the Kingdom Hearts series, a former apprentice of Ansem the Wise, and the original persona of Ansem, Seeker of Darkness and Xemnas. It's revealed in Kingdom Hearts Birth by Sleep that Xehanort was "born" when his original incarnation, Master Xehanort's heart took over the Keyblade Wielder Terra's body. Xehanort is directly responsible for the creation of the Emblem Heartless, the Nobodies, and Organization XIII, and also indirectly responsible for putting most of the Disney villains on the hunt for Kingdom Hearts. One way or another, Xehanort has made an appearance in every game of the "Xehanort Saga". Similar to the Organization XIII members, Xehanort's name contains the letter "X", along with anagrams for "No Heart" and "Another". Before he lost his memory, when he still had a split personality, he was known as Terra-Xehanort or the new Xehanort. Also, he is the true leader behind the Villain League, and is an old ally to Chernabog and Malefor.

Kingdom Hearts Birth by SleepEdit
Xehanort first appeared chronologically in Kingdom Hearts Birth by Sleep at the Keyblade Graveyard when Master Xehanort used his Keyblade to unlock his heart and possess Terra after the creation of the χ-blade. He sought to use Terra's body as a younger and more powerful weapon as he ventured deeper into the mystery of the Keyblade War. Terra failed to shield himself with his armor, becoming a younger incarnation of the elderly Keyblade master. As he walked off, the possessed Terra was forced to battle Terra's discarded armor, which had come alive through Terra's mind. After the fight, Terra-Xehanort was knocked unconscious and was then sent to the Radiant Garden in a blast of light caused by the destruction of the χ-blade (and Vanitas) by Aqua and Ventus. The discarded armor continued to reside in the Keyblade Graveyard from then on, Kingdom Hearts vanishing above it.

Aqua, learning from Master Yen Sid that her friend Terra's heart had been lost, was led to Radiant Garden through Terra's voice after hearing it when she left a comatose Ventus to rest peacefully in a chamber in the newly reshaped Land of Departure. It was in the Radiant Garden that Aqua met Terra-Xehanort. Confused about his identity (due to the conflicting hearts Terra and Master Xehanort within him) Terra-Xehanort attacked Aqua with Master Xehanort's Keyblade and a Heartless-like symbiote. After the climatic battle, Terra begins to get the upper hand in his and Master Xehanort's internal struggle, which forces Terra-Xehanort to use the Keyblade to force him out. However, the symbiote drags Xehanort into the Realm of Darkness, Aqua diving in after him and sacrificing her armor and Keyblade to save Terra-Xehanort. After these events transpired, Braig took fellow apprentice Dilan as well as their master Ansem the Wise to the location of the battle between Aqua and Terra-Xehanort, where the amnesiac Keyblade wielder lay unconscious with no memory at all, except the name "Xehanort". On Ansem's order, the amnesiac young man was taken back to the castle along with Aqua's armor and Keyblade.

As the years passed, Xehanort became Ansem's leading apprentice, showing remarkable talents and having a great curiosity about the true nature of the heart. He also began to work with Braig, who would begin to construct a plan to mass produce the nefarious Heartless alongside him. Little was Xehanort aware that inside him a battle between the hearts of Terra and Master Xehanort was taking place, the two arguing over who was to control Xehanort's body. ===Between Kingdom Hearts Birth by Sleep and Kingdom HeartsEdit=== Although he was confused about his past, Xehanort's quick learning and cunning made him the foremost apprentice of Ansem the Wise. Xehanort was described by Ansem as having abilities so remarkable that they could be considered supernatural. Eventually, Ansem began to worry about the darkness that lingers within the hearts of others and sought a way to stop it before it consumed his people. Ansem constructed a laboratory under his castle where he, Xehanort, and Ansem's five other assistants (Braig, Dilan, Even, Aeleus, and Ienzo) would conduct experiments on darkness.

Xehanort, who Ansem now fully trusts as an apprentice and friend, offered to use himself in the experiments. Ansem also hoped to unlock Xehanort's memories in addition to uncovering a way to repress the darkness within hearts. Xehanort had other plans in mind though and decided to conduct his own experiments to go deeper into the research.

Xehanort, Braig, Dilan, Even, Aeleus, and Ienzo carried out their own experiments where they abducted countless people and locked them within the depths of the laboratory where Xehanort then conducted horrible experiments on the subjects. After using many test subjects, one set of experiments led to the collapse of their hearts. The subjects then went into unrecoverable conditions and were locked up in the dungeon of the castle. Eventually, Xehanort checked on the subjects and saw that they transformed into creatures of darkness, which he named "The Heartless" as they apparently lacked hearts. At this point, Xehanort had taken Ansem the Wise's name as his own and wrote his own report under this stolen name.

Xehanort then presented the Heartless with living and non-living samples; the Heartless only responded to the living. Xehanort witnessed the Heartless consume the living creatures and then multiply into more Heartless. Xehanort deduced that the Heartless seek the hearts of other things, which explains why they only react to living samples, in order to create more of their kind. Xehanort and his associates soon began to slowly accept the darkness, allowing them to have limited control over the Heartless.

They in turn began to look less and less human, a factor that Ansem himself realized. When Ansem learned that his apprentices continued with the research, he called them together and ordered for them to cease their efforts immediately, all the while questioning what was happening to his loyal apprentices. Xehanort, however, saw his master as a fool who had no understanding of research and kept the research operating.

After observing the behavior of the Heartless and their responses to living things, Xehanort took one of the Heartless aside and observed its behavior. The Heartless began to move throughout the castle until a door appeared which Xehanort was, somehow, able to open. Behind the door was a humongous mass of energy to which the Heartless reacted immensely. The opening of this door led to the collapse of the world's boundaries, which was seen in the form of a meteor shower. Xehanort eventually deduced that the door actually led to the heart of that world and that the opening of this door led to the collapse of the walls between worlds.

This allowed inter-dimensional travel as all the walls between worlds were now broken and eventually a visitor showed up named King Mickey. He had constructed a Gummi Ship, a spacecraft capable of breaking through world boundaries, out of materials from the meteors and used it to visit many different places in search of answers of recent events. Xehanort and Mickey met and had huge discussions in which Xehanort learned of the Keyblade, a mysterious weapon that Mickey himself possessed.

There were also legends that told of seven princesses with pure hearts and how they have a connection to this Keyblade. The Keyblade can also be wielded by many, as long as their hearts qualify, and it seems there is a legend of one Keyblade bearer who went on a journey of destiny to seal off the doors to other worlds. Since this was not in Xehanort's interest, he sought a way to find this weapon, which is ironic, given that his former self once wielded one, but was now lost. Mickey eventually met and befriended Ansem the Wise and the two of them exchanged theories and ideas in his office about what the Heartless were after. Ansem decided to resist the urge to test their theories while expressing deep remorse for his actions.

However, Ansem had no idea that Xehanort had gone further than he himself even dared. Xehanort entered the office during their discussion, asking Ansem's permission to test an experiment. Ansem forbade Xehanort to conduct it and told him to forget everything he learned from the research.

Even though Ansem had no further urge to research the darkness, the experiments led by Xehanort continued including the creation of a machine that created artificial Heartless, all of which were marked with an emblem created by Xehanort in order to differentiate them from the pure-bred Heartless. King Mickey suspected something odd about Xehanort and told Ansem to check his lab, collect all his data, and see if everything was under control.

Ansem did so and learned that Xehanort had taken his name as his own and wrote a detailed report. From the report, Ansem learned of the horrible torture inflicted on people by the inhumane experiments that Xehanort had done. Ansem ordered his apprentices to seal off the laboratory and cease their scheme for knowledge.

Ansem's apprentices did as he instructed them but Xehanort eventually banished Ansem to the Realm of Nothingness and ravaged the world with Heartless. The Heartless under the command of Xehanort began spreading to other worlds and destroyed numerous ones in their mad search for hearts. One side effect of the destruction of so many worlds was the creation of Traverse Town, made up of the remains of the ruined worlds and populated by the few survivors of those said worlds. Xehanort then ordered for the seal on the laboratory to be broken and that a room that he called the "Chamber of Repose" be constructed. Once done, Xehanort often went in and spoke as if there was someone else in the room. It is later revealed that the room housed Aqua's armor, which Xehanort used to help gain further recollection about his past.

Xehanort then abducted and sent Kairi, a resident of Radiant Garden, to the oceans of other worlds. The reason for this was because Xehanort thought Kairi had a connection to the Keyblade bearer, as she seemed to possess power comparable to that of a Princess of Heart, which is rumored to posses a connection to the Keyblade. He hoped to use her to find the Keyblade master and prevent him from sealing off the doors to other worlds.

Xehanort made the final pages of his report, which outlined his intentions as well as those of the Heartless. The Heartless seek to consume the hearts of all living things. However, they not only seek human hearts, but the hearts of the worlds themselves. Their ultimate goal is to collect enough hearts to form the biggest heart of all, the heart in which all that exist are evolved from: Kingdom Hearts. Xehanort decided to use the Heartless' instincts to make his own plans.

He would find Kingdom Hearts in order to gain ultimate power, control, and knowledge. Xehanort also learned that the creation of a Heartless can also lead to the creation of another creature called a Nobody, beings that are left over bodies of those whose hearts have been stolen away. They transform into an inhuman state and do not truly exist as they lack a heart to make them truly live.

Xehanort and the others eventually gave themselves to the darkness to gain the ability to control all Heartless and wield the powers of darkness. They lost their hearts in the process and they became powerful Nobodies. However, Xehanort was the only one to have both a human Heartless and a human Nobody, both possessing the memories and personality traits prior to their creations. Since they possessed strong hearts, Xehanort and his followers (Braig, Dilan, Even, Aeleus, and Ienzo) were able to retain their human forms as Nobodies. Radiant Garden was almost completely destroyed, save for the castle and the mutated waterways, which had several modifications done to it by Xehanort and the other apprentices, and most of its people were wiped out while some (like Leon, Aerith, Yuffie, Cid, and Merlin) managed to escape to Traverse Town.

Kingdom Hearts IIEdit
While Sora was investigating Ansem the Wise's study within Hollow Bastion, he spots a portrait of an unnamed man. He and his friends (Donald Duck and Goofy) realize that this man was the original being of "Ansem", who Sora had defeated one year ago. After speaking with Tron and learning more about Ansem the Wise, they return to Ansem's study and run into King Mickey, who indicates that the true Ansem was not the one they fought. He asks them to give Tron some further help, and once they return, they find an image of an unknown man on Tron's computer, which Mickey identifies as a picture of the real Ansem. Later, after defeating the Heartless swarming the town, the trio encounter Xemnas, the Nobody of the fake Ansem and the superior of Organization XIII. Mickey finally remembers that Xemnas's original being was Xehanort, and explains about his past encounter with Ansem and Xehanort.

In The World That Never Was, King Mickey encounters the true Ansem, and learns from him that his goal is to destroy Xemnas's artificial Kingdom Hearts and exact revenge on Xehanort for stealing his name and pride. Riku and Sora also refer to the fake Ansem as "Xehanort's Heartless", when Sora mistakes Riku for the villain, and when Riku explains how he had gained Ansem's form. Later on, Ansem repeatedly uses the name "Xehanort" to insultingly refer to Xemnas, who replies by listing Ansem's own sins, and accusing Ansem of always holding his research back. Xemnas's demise at the hands of Sora and Riku apparently ends the threat of Organization XIII, yet also paves way for Xehanort's eventual return.

Role in the series
Xehanort is the real Big Bad behind Mirage's scheme, for once she activates the seven Princesses of Heart at the Mountain of Darkness to free Malefor, Xehanort will instead be summoned to get rid of Mirage and Maleficent, and turn Cynder into Dark Cynder, and then into his new body so that he will become all powerful. This could be the real plan that Scroopfan is using, or this could just be an unofficial backstory. Who knows? And it is unknown whether or not Xehanort will appear in the series at all.