Xehanort

Master Xehanort is the original master of Ventus, the creator and master of Vanitas, and the original incarnation of Xehanort. He is a Keyblade Master and the main antagonist of Kingdom Hearts Birth by Sleep.

Kingdom Hearts Birth by Sleep
''One of the true Keyblade Masters and a longtime acquaintance of Master Eraqus. He is connected with the masked boy, and harbors a hidden agenda.''

Unlike Master Eraqus, Xehanort believes darkness need not be rejected if it can be controlled.

Kingdom Hearts Birth by Sleep
In his youth, Xehanort, who once lived on a beach, had dreams of leaving his home in search for something greater. At some point he found a way to depart his home world and was trained to be a Keyblade Master, eventually befriending Eraqus, another Keybearer, whom he began to see as a younger brother. Throughout his life, Xehanort traveled to many different worlds and obtained vast knowledge concerning Keyblade lore, the power of Light and Darkness, a detailed knowledge of the Heartless, the mysteries of the Keyblade War and Kingdom Hearts. Realizing the power unlocking the "heart of all worlds" would grant, Xehanort set his goal on finding a way to open the door to Kingdom Hearts. He eventually discovered a way of doing so: forging the χ-blade, a legendary Keyblade capable of unlocking Kingdom Hearts. One day, when he discussed his plans to forge the χ-blade with Master Eraqus, he was met with opposition from the latter, who insisted that his plan was too dangerous. This discussion quickly escalated into physical violence, which ended when Xehanort used the powers of darkness to scar Eraqus' face.

By this time, Master Xehanort had grown old, and realized that he must transfer his essence and knowledge to a "new vessel" in order to survive to see his plans reach fruition. To accomplish this, he sought out an apprentice and found the boy Ventus, who he began training as Keyblade wielder with the intent of pitting him against one of Master Eraqus's students of light, forging the χ-blade, and to eventually use him as his vessel. However, Ventus proved to be a poor candidate, and when he refused to use his darkness to fight several Heartless, Master Xehanort instead decided to use him as part of his ultimate plan: using his Keyblade, Master Xehanort extracted the darkness from Ventus's heart, forming a sentient being of pure darkness who assumed the name of "Vanitas." With these two boys, Master Xehanort intended to forge the χ-blade.

Unfortunately, the process left Ven in a comatose state with his broken heart of pure light slowly fading out. Master Xehanort (in a black coat) decided to leave Ven to live out his last days peacefully in his old home, the Destiny Islands. To his master's surprise, Ventus's heart somehow survived and Xehanort realized the boy could still be of use. However, Ventus was still far too weak in comparison to Vanitas, for the two needed to be equal in power for the creation of the χ-blade. Additionally, Xehanort realized that he could not train Ventus and Vanitas together, as Vanitas's darkness would eventually consume and completely destroy Ventus's light. Master Xehanort ultimately left Ventus in Eraqus's care, to let him train and grow stronger.

At this point, Master Xehanort set his eyes on one of Master Eraqus's apprentices: Terra, within whom he sensed the correct potential to be his new vessel. While in the Land of Departure, Master Xehanort sabotages the Mark of Mastery Exam taken by Terra and Aqua, causing Terra to fail, and later tells him that if he were to become a true Keyblade Master, he would have to embrace the darkness in his heart and channel it rather than fight it. Shortly thereafter, Master Xehanort and Vanitas disappear on an apparent quest to find the Princesses of Heart.

During his travels, Master Xehanort manipulates Master Eraqus's apprentices (Terra, Aqua, and Ventus), who had been sent to find him and destroy the Unversed, a malicious species created as a side-effect of Vanitas's existence, and at the same time, comes into contact with and also manipulates the evil fairy, Maleficent, into beginning a quest to capture the seven Princesses as a fail safe. He encounters Terra in the Keyblade Graveyard and puts his manipulative skills to the test, explaining the reason for his actions: He is trying to safeguard the light from the "demon" he unleashed. He then tells Terra an altered version of Vanitas's origins: supposedly, Vanitas was created when Ventus was overtaken by his darkness and Master Xehanort extracted Ventus's darkness in a desperate attempt to save him, severely damaging Ventus' heart in the process. Ashamed, Xehanort left Ventus in Master Eraqus's care.

Though he had attempted to keep Vanitas contained, the dark enigma escaped and began spreading the Unversed throughout the worlds. Master Xehanort then asked Terra to help him stop Vanitas and atone for his mistake. Terra agrees, and is instructed to search in the Radiant Garden, where Vanitas will undoubtedly strike next.

He next travels to the Radiant Garden and strikes a bargain with Braig, who desires the Keyblade for himself. Afterwards, Master Xehanort stages his own capture and has Braig fight Terra, with Terra succumbing to the darkness and injuring Braig, blinding the young man in the right eye and scarring his face. Master Xehanort tells Terra that he shows the true Mark of Mastery as he was able to channel the darkness instead of rejecting it and that Eraqus will never accept it out of his fear of darkness. He then goes on to state his belief that light and darkness are a balance that must always be maintained. He then gives Terra an opportunity to be his pupil, claiming that they can do the worlds much greater good by wielding light and darkness in equal shares. Master Xehanort then pulls the final string, calling him by the name "Master Terra" and gaining the young man's trust.

Later on, Master Xehanort has Vanitas abduct Mickey Mouse as bait to lure Ventus to the Keyblade Graveyard, where he reveals to him the truth about his past, also stating that Master Eraqus knows about it. While Ven goes to see Eraqus, Xehanort tells Terra that Ventus went to see Eraqus about his past, and is worried he may force the truth out of him. He also tells him that Eraqus has gone mad and is about to destroy Ventus. Terra is tricked into defeating Master Eraqus in battle, allowing Xehanort to cruely deliver the finishing blow to his former friend. Master Xehanort then tells Terra to go to the Keyblade Graveyard where he will see Aqua and Ventus for the last time before falling prey to the darkness. He then covers the Land of Departure in darkness, completely destroying the world and leaving nothing but the castle's remains, telling Terra he would not need a home where he is going.

Soon enough Terra, Aqua, and Ventus discover the truth and confront Master Xehanort and Vanitas at the Keyblade Graveyard (the remains of the legendary Keyblade War). There, Master Xehanort reveals to them his true plans to create the χ-blade and unlock Kingdom Hearts. In the ensuing battle, Master Xehanort freezes Ventus, and when Terra reaches Master Xehanort, he demands to know what really happened to Ventus's heart. Master Xehanort gladly reveals that he intentionally shattered Ventus's heart and created Vanitas. Terra becomes enraged, and battles Xehanort and Vanitas. Mid-way in the fight, Master Xehanort commands Vanitas to fuse with Ventus and kill Aqua. Terra tries to stop Vanitas, but is impeded by Master Xehanort, who gleefully tells Terra that he is powerless to save them, and that he should use his rage and despair to empower himself. Terra, enraged that Xehanort would destroy his "father" Eraqus and go after his friends, loses control of his anger and succumbs again to the darkness in his heart.

Terra uses the power of darkness to defeat the elderly Keyblade master, but Xehanort enacts his final scheme and uses his Keyblade to unlock his own heart and transfer it into Terra's body, prolonging Xehanort's life and transforming Terra into Terra-Xehanort, while Master Xehanort's original body fades out of existence with a triumphant smile.

Blank Points
The hearts of Master Xehanort and Terra are shown disputing over internal dominance within the second Xehanort. Despite Master Xehanort's insistence that he will soon incorporate Terra's heart into his own, Terra remains confident that he will win over and eventually expel Master Xehanort, who realizes that Terra is harboring the heart of Master Eraqus. Despite this, Master Xehanort shows no concern and reveals to Terra that possessing him was merely one of many roads he chose to take.

Kingdom Hearts Re:coded
After Mickey returns to the Mysterious Tower with the news that they have located Ventus's heart, Yen Sid explains that with the destruction of "Ansem" and Xemnas, Xehanort has been revived, and this will eventually lead to the return of Master Xehanort.

Appearance
Master Xehanort appears as an old man, bald except for thin eyebrows and a curled, silver goatee. His ears are pointed and his eyes are yellow. He has broad, hunched shoulders and a crooked back. He overall appears as a somewhat feeble old man, certainly deceiving given his immense power.

His attire is nearly identical to the clothes that Ansem, Seeker of Darkness wears, namely, a white and black cloak with a red inner lining, a white shirt with two thin black belts, white gloves and calf-high black boots, similar to those worn by Ansem the Wise's apprentices. The only major difference in appearance between them is that Ansem has his chest bared, along with his emblem on the front, while Master Xehanort does not. There are a few minor changes as well - Ansem's cloak has a gold lining on the edges, while Master Xehanort's cloak has black ones. This is later carried on to Ansem, explained because this particular Heartless was made from the heart of Master Xehanort.

Master Xehanort's previous attire is briefly shown as a Black Coat, as a predecessor to the attire of Organization XIII.

In his youth, Master Xehanort had mildly tanned skin, golden eyes, and silver hair which both slightly spikes and falls past his shoulders in the back; it is styled similar to Xehanort's, albeit with four bangs framing his face - the back two thicker than the front two - and the two backwards spikes on the sides are absent, the topmost one slicked back. He wore the same style of white shirt, which only reaches to his thighs, a black vest with a high collar, long armbands which cover his forearms, and dark grey pants stuffed into his boots, similar to those worn by Organization XIII but absent of the silver lining on top, much like those worn by the guards of Radiant Garden.

Personality
Much like Xehanort, "Ansem", and Xemnas, Master Xehanort is shown to be a cunning, callous, and pragmatic being with the sole goal of merging with Kingdom Hearts, the lives of innocent people and even his closest friends meaning absolutely nothing to him. To this end, he is willing to put whatever he pleases on the line or destroy anything in his way, demonstrated when he manipulated several characters such as Terra, Aqua, Ventus, Braig, and even Maleficent; creates Vanitas, a sentient being for the sole purpose of forwarding his evil plan; and slays his old friend, Master Eraqus, in cold blood after tricking Terra into defeating him in battle.

Despite his overweening malice, Xehanort has been shown to have some slight sympathy for his victims, such as when he takes pity on Ventus, following the rupture of his heart, and decides to leave him to die a peaceful death on Destiny Islands. All of Master Xehanort's other positive points are revealed to have sinister intentions behind them, demonstrated when he only took Ventus as an apprentice and cared for him solely with the intention of making the boy his vessel once he was strong enough, and only accepted Master Eraqus's invitation to witness the Mark of Mastery Exam to sabotage it and put Terra on the path to darkness so as to make him his new vessel after deciding to instead use Ventus for the X-Blade.

Overall, Master Xehanort is the true catalyst of all the events in the series so far, and appears to be the most evil and dangerous of all of Xehanort's forms. He shares most of his personality traits with Xehanort (before the latter's fight against the Lingering Will and Aqua) and "Ansem", while Xemnas appears to be influenced several times by Terra's characteristics. He has a few unusual tendencies and quirks, however, such as turning away from the people he speaks to, or over-dramatizing his hand gestures when delivering a speech, even flexing his fingers in an unusual manner, as if itching to grab something.

Abilities
His age often causing opponents to underestimate him, Master Xehanort is an extremely skilled Keyblade Master and magic user. Able to teleport if he is in danger, Master Xehanort strikes opponents with powerful, fast-paced combos. He also can bombard foes with Thunder, Blizzard, and Earth-based magic. His magic skills are some of the most advanced seen in the series so far, able to create massive rock formations and pillars, encase Ventus's body in ice, project a gust of wind powerful enough to send Ventus and Mickey flying from his hand, block Braig's Arrowgun shots without raising his arms, and telekinetically control the Keyblades covering the Keyblade Graveyard to attack Terra and Aqua. He also possesses physical strength sufficient enough to grab a fully-armored Ventus by the back of the head and lift him into the air with one hand.

Master Xehanort shows a great deal of skill in utilizing the heart and its capabilities, able to create a living being, Vanitas, out of the darkness of Ventus's heart when he unlocks it and even able to direct his heart into Terra's body to possess it after his defeat in the Keyblade Graveyard.

Once he becomes the young man known as Xehanort through the possession of Terra's body, Master Xehanort proves to be the stronger of the two hearts residing within him. Master Xehanort's overpowering Terra's is demonstrated several times during the battle between Terra-Xehanort and Aqua, Master Xehanort's influence beginning the fight in the first place and even releasing Terra's heart from within the body of his younger incarnation when Terra begins to regain control.

Weapon
Master Xehanort is able to wield his Keyblade with great skill despite his age, and enough of his strength has remained over the years that he is able to use it in fast-paced physical combos. His battle pose is similar to that of both Vanitas and Riku, but he mainly allows the Keyblade to hang loosely at his side as he walks slowly towards opponents. Master Xehanort also uses his Keyblade to unlock countless hearts, including his own.

When Master Xehanort possesses Terra's body to become Terra-Xehanort, he abandons Terra's Keyblade and replaces it with his own. Terra-Xehanort wields the weapon with great skill, combining several of Terra and Master Xehanort's abilities to form his own deadly combos. As this Keyblade was gained by Terra-Xehanort through Master Xehanort's heart's more powerful influence, it is also used through Master Xehanort's influence to unlock Terra-Xehanort's heart.

Quotes

 * "This world is just too small."
 * "Empty creature from Ventus riven... to you, the name Vanitas shall be given."
 * ""χ"... A most ancient letter. Some say "kye," but the meaning is the same. Death... A letter that spells endings."
 * "Behold... These lifeless keys used to be full of power— united with the hearts of their masters. On this barren soil, Keyblades of light and darkness were locked in combat...as a great Keyblade War raged."
 * "Countless Keyblade wielders gave up their lives, all in search of one, ultimate key. And it will soon belong to me... χ-blade."
 * "You see how powerless you are to save them? Savor that rage and despair. Let it empower you!"
 * "Why I did him a favor and freed the darkness inside him, alas, poor Ventus never had the fortitude for such strenuous trials."
 * "Let all that anger out, my boy. Give your heart over to darkness!"
 * "Still so blind... Then I will make you see!"
 * "If you could have seen the fury in his eyes... I'm certain he's capable of anything. I fear the boy will force the truth out of Eraqus."

Trivia

 * In the English version of Kingdom Hearts Birth by Sleep, Master Xehanort is voiced by Leonard Nimoy, who was chosen by Tetsuya Nomura specifically for his role as Spock in the Star Trek franchise. This was Nimoy's final acting role before his retirement in 2010.
 * In the Japanese version of Kingdom Hearts Birth by Sleep, Master Xehanort is voiced by Chikao Ohtsuka, who was chosen by Tetsuya Nomura specifically because he is the father of Akio Ohtsuka, the Japanese voice actor of Xehanort and "Ansem". Chikao Ohtsuka also previously voiced Captain Hook in the original Kingdom Hearts but was replaced by Naoya Uchida for Kingdom Hearts Birth by Sleep.
 * In Kingdom Hearts Birth by Sleep, Yen Sid states he had hoped Master Xehanort's Heart wouldn't lead him astray again. This is a sign that the two have possibly met before, as Yen Sid is revealed to be a former Keyblade Master and an acquaintance of Master Eraqus.
 * Master Xehanort being told by Terra in Blank Points, "You're gonna get shown the door, old man" is a bit of foreshadowing towards the climax of the first Kingdom Hearts, in which Ansem, Seeker of Darkness, made from the heart of Master Xehanort, is shown the Door to Kingdom Hearts itself, which engulfs him in Light and destroys him completely.