Master Xehanort

"But, darkness did cover the world once, in legend. We know so little about the Keyblade War, only that it was just the beginning. Amidst that crisis, a precious light was found. It is a curious tale and one worth exploring. They say ruin brings about creation. So what, then would another Keyblade War bring? When the darkness falls, will we be found worthy of the precious light the legend speaks of? I must have these answers. The χ-blade needs to be forged and with it, the door to the Keyblade War unlocked."

- Master Xehanort describing his long term goal.

Master Xehanort is the main antagonist of the Dark Seeker Saga, the first part of Kingdom Hearts franchise. He is the original incarnation of Xehanort from which Ansem, the Seeker of Darkness, Xemnas and all others spawned from. He manipulated almost every event in the series, and devised many backup plans that involve dividing his heart among 13 different beings created from his power and take over the universe. Followed the order of the timelines and events, he can be considered as the overall main antagonist of the franchise so far.

Master Xehanort was a Keyblade Master, the first master of Ventus, and the creator and master of Vanitas, the original incarnation of Ansem and Xemnas and the future self of Young Xehanort. He served as the main antagonist and final boss of both Kingdom Hearts: Birth by Sleep and Kingdom Hearts III and the central antagonist of Kingdom Hearts 3D: Dream Drop Distance, being the true villain who has orchestrated the whole event.

In Birth by Sleep and Dream Drop Distance, Xehanort was voiced by the late Leonard Nimoy in the English dubbed version, who also played Sentinel Prime in the Transformers series and the late Chikao Ōtsuka in the Japanese dubbed version. In Kingdom Hearts III, he was voiced by Rutger Hauer in the English dubbed version, who also played Wulfgar in Nighthawks, Roy Batty in Blade Runner, Lothos in Buffy the Vampire, John Ryder in The Hitcher, Huntsman in The 10th Kingdom and Patrick Henry Roark in Sin City, and Akio Ōtsuka in the Japanese version, who is Chikao Ōtsuka's son and also notably does the role of Ansem, Seeker of Darkness, and Terra-Xehanort as well as the voice of Marshall D. Teach in One Piece.

Backstory
Xehanort was born in Destiny Islands, feeling his home was a prison. But due to an encounter of a future incarnation of himself, Xehanort's destiny was set in stone as he acted on his future self's will before losing his memory and leaving the islands to become an apprentice under a Keyblade Master alongside a fellow apprentice named Eraqus. When the two became Keyblade Masters, Eraqus was made steward of the Land of Departure so Xehanort can freely travel the worlds.

However, over extears of research and travel, Xehanort became obsessed with the events of the Keyblade War. He felt that there was no balance between the light and the darkness, so he planned to recreate the χ-blade to cause a second Keyblade War with hopes to establish balance. By the time he confided his goals to Eraqus, Xehanort had mastered the powers of darkness and used them to scar his former friend in defense.

He attempted to utilize the darkness of a Keyblade wielder named Ventus to recreate the χ-Blade and serve as a host for his heart to prolong his life long enough for his plan to come to fruition. However, Ventus refused to succumb to his darkness and Xehanort is forced to extract the darkness and create Vanitas before leaving a weakened Ven to die on the Destiny Islands.

But, seeing the boy pulling through, Xehanort has Ven sent to be trained by Eraqus so he can become Vanitas' equal in order for their reunion to recreate the χ-blade. By that time, Xehanort found a more ideal host in one of Eraqus' two students: Terra.

Birth by Sleep
While Vanitas traveled the worlds spreading the Unversed to prepare Ventus for their reunion, Xehanort was looking for the Princesses of Heart (seven princesses with hearts of pure light). He managed to find one, Princess Aurora. It was also at that time that he arranged for Maleficent to find the other Princesses of Heart for him.

He also came to Radiant Garden to employ the services of Braig, offering him a Keyblade of his own in return for helping him in getting Terra to embrace his darkness.

Though Braig was scarred as a result of Terra using his darkness, winning the youth's trust as a result, Xehanort threateningly calmed him down before infusing part of his heart into Braig's body. By tricking Terra into defeating Eraqus, Xehanort kills his old friend and casts the entire Land of Departure into darkness before telling Terra to meet him in the Keyblade Graveyard where his plan will be completed.

Managing to separate Terra from the others, with Braig holding them off, Xehanort sends Vanitas to enact his reunion with Ven. Managing to get Terra to unleash his full fury on him before seeing the light marking the restoration of the χ-blade, Xehanort uses his Keyblade to transfer his heart into Terra's body, turning the youth into his vessel Terra-Xehanort.

However, with a new younger body, Xehanort found resistance from Terra through both his Lingering Will and the heart of Terra itself as he attempts to aid Aqua. It was only when Terra-Xehanort attempted to purge Terra's heart that the vessel loses all his memories except the name "Xehanort" which he took.

However, unable to fully rid himself of Terra, Xehanort reveals the series of backup plans he arranged that were ultimately carried by Terra-Xehanort's splinter selves, false Ansem and Xemnas. Even though Sora and his friends foil their schemes, Xehanort had another plan set into motion.

Signs of What's Next
After the defeat of Ansem and Xemnas, Yen Sid explains to King Mickey that those actions actually freed Xehanort's heart from the Heartless Ansem and vanquished Terra-Xehanort's leftover body which had become his Nobody Xemnas, thus both halves' destruction has now lead to the reconstruction of Xehanort's pure and original incarnation: Master Xehanort.

Dream Drop Distance
Having expecting it, Xehanort arranged for his past self to gather every incarnation or vessel of himself together at the World That Never Was to witness Master Xehanort's return while capturing Sora as he and Riku were in the Sleeping Worlds. Eventually, ten Xehanorts, which included his Heartless and Nobody as well as Braig and Isa, were gathered.

When Riku arrives to rescue Sora, who is in the Organization's clutches, King Mickey freezes time to allow Riku to escape. However, Master Xehanort's soul possesses his younger self and duels Riku.

After the battle, Master Xehanort finally revives. Xehanort callously admits he misjudged the χ-blade being recreated with only Ventus and Vanitas, stating that their fate, along with Aqua and Terra's, was all predestined. He further elaborates that his Thirteen Seekers of Darkness, the true Organization XIII, with be able to recreate the χ-blade by clashing with seven lights, the seven wielders of the Keyblade. Though Xehanort attempts to add Sora to his rank to complete the members, Lea's interference ruins it as he and his followers scatter, but he promises that the final battle will come soon.

Kingdom Hearts III
Master Xehanort appears as the main antagonist of Kingdom Hearts III, the finale of the Dark Seeker Saga.

Master Xehanort first appears approaching the guardians of light once they arrive at the Keyblade Graveyard for the final showdown. He and his direct incarnations repeat his speech to Eraqus about the χ-blade and the Keyblade War from years ago before summoning thousands of Heartless to attack them.

Master Xehanort appears again later on, this time with the rest of the Real Organization XIII by his side. Declaring that the χ-blade would be forged, Xehanort creates a massive labyrinth, the Skein of Severance, keeping most of the key players inside while his Heartless, Nobody, and younger self watching just shortly overhead, with Xehanort himself watching all from a large pillar.

After the other darknesses are defeated, Sora, Riku, and Mickey confront Ansem, Xemnas, and Young Xehanort at the Tower of Endings. Master Xehanort reveals that the battles between light and dark, and the subsequent defeat of those darknesses, created nine out of thirteen keys needed to forge the χ-blade, watching as his other incarnations are defeated, leaving just one left. Xehanort, having planned for every eventuality, brings out Kairi, whom Xemnas had kidnapped earlier. In order to motivate Sora to fight him, Xehanort mercilessly slays Kairi in front of him. Sora tearfully and angrily attacks Xehanort, creating the thirteenth key. Mickey and Riku attack him as well, but are easily repelled. Xehanort opens Kingdom Hearts and with the thirteen keys, his own Keyblade, No Name, transforms into the χ-blade. Having obtained the χ-blade at long last, Xehanort uses its power to corrupt Kingdom Hearts into darkness.

However, because his younger self had frequently traveled through time, Xehanort himself served as a portal, something the guardians of light use to their advantage. They trap Xehanort within himself, and while the other guardians keep Kingdom Hearts at bay, Sora, Donald, and Goofy go inside the portal to Scala ad Caelum, the old training grounds for Keyblade wielders where Xehanort and Eraqus themselves became Keyblade Masters. There, the trio find that the defeat of the other twelve Organization members created Replica Xehanorts, twisted shells that Xehanort uses to power himself up for the final battle. In his Armored Form, Xehanort battled the trio throughout the city before they shattered his armor. Xehanort teleported up to the top of the tower, wielding the χ-blade as Sora, Donald, and Goofy battled him one last time.

Near the climax of their battle, Xehanort nearly kills Sora during his final attack, but Donald and Goofy managed to bring him back from the brink and unite for one final attack, Trinity Limit, defeating Xehanort and fatally wounding him. However, Xehanort still refuses to give up, stating it is too late to stop Kingdom Hearts, revealing he used it to trigger a purge that would destroy all the worlds and remake them free of darkness, and that he alone would lead the new era. Sora rejects his claims saying it was not his decision to make, and even after the other guardians arrive, Xehanort still holds onto his desires. But to his own surprise, Terra steps forward saying "There's more to light than meets the eye", something Eraqus told him in their youth, right as Eraqus appears from Terra, his heart being in Terra the entire time, telling Xehanort to hand over the χ-blade. Xehanort eventually concedes, giving in to his old friend and handing the χ-blade over to Sora. Eraqus and Xehanort then go together to the afterlife, having repaired their fractured friendship in his final moments.

Kingdom Hearts Unchained χ
Master Xehanort appears on a number of attack medals in Kingdom Hearts Unchained χ, especially Magic medals.

Trivia

 * Both Xehanort's actors (in both English and Japanese) died and were replaced.
 * According to Nomura, Kingdom Hearts III is the last game where Xehanort is the villain.
 * Master Xehanort is the overarching and most recurring antagonist in the series so far, as every incarnation of him is the main antagonist in each game except Kingdom Hearts Coded although one of his incarnations was indirectly responsible for the events that took place in the game: Xehanort himself is the main antagonist in Birth by Sleep and Kingdom Hearts III. Young Xehanort is his teenage self and the central antagonist in Dream Drop Distance. Through his Terra-Xehanort incarnation, Ansem, Seeker of Darkness is his Heartless and the main antagonist in Kingdom Hearts and Xemnas is his Nobody and the main antagonist in Kingdom Hearts II.
 * It was mentioned in Kingdom Hearts III by Mickey to Riku that if Ansem, Seeker of Darkness, and Xemnas had been the Heartless and Nobody of Master Xehanort (and not Terra-Xehanort) then they would be just as old as he is instead of being younger like they had been.