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 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.

He was voiced by the late Leonard Nimoy in the English dubbed version, and the late Chikao Ōtsuka in the Japanese dubbed version.

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 use 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 and after
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 will appear as the main antagonist of Kingdom Hearts III, the finale of the Dark Seeker Saga.

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

Quotes
"Once a seat of power for all Keyblade wielders, here, I and my other selves can be one...in Scala ad Caelum."

- Master Xehanort in Kingdom Hearts 3

"We are out of time. Neither the union of light nor darkness has been achieved, and we must all return whence we came. But, the gathering of the seven and thirteen is nigh. Let us finish this at the fated place, once your lights and my darknesses have joined together!"

- Master Xehanort leaving with the new Organization.

"Darkness can not be destroyed. It can only be channeled."

- Master Xehanort to Terra.

"But once again you have it all wrong, Eraqus. Darkness is a beginning, you see, not an end. At birth, every one of us emerges from darkness into a world of light, do we not?"

- Xehanort arguing with Eraqus.

"Not your concern."

- Xehanort when Eraqus asked him if the darkness has taken him.

"No. It is because you are trying to hold it in. Let the dark impulses waken in the pit of your heart. Release them, here and now! Sharpen your fear into rage. You must! If you do not let the storm within you run its course, it will wipe you from the face of the world, make no mistake! Do it. Embrace the darkness. Produce for your Master the χ-blade!"

- Xehanort trying to get Ventus to succumb to the darkness.

"Really? You would rather die than use the power? Feckless neophyte. If I must... I will extract the darkness from within you myself."

- Xehanort right before creating Vanitas.

"Empty creature from Ventus riven... to you, the name Vanitas shall be given."

- Xehanort naming Vanitas.

"There, you see? An empty world, like a prison. I imagine you'll be right at home."

- Master Xehanort leaving Ventus on Destiny Islands.

"What do you make of Ventus?"

- Xehanort asking Vanitas what he thinks of Ventus.

"Not here, you won't. I have to keep up appearances."

- Xehanort telling Vanitas to provoke Ventus somewhere else.

"Yes. You are indeed strong. The darkness is nothing to fear."

- Xehanort talking to Terra after the Mark of Mastery exam.

"Terra, come see me at once."

- Xehanort beckoning Terra to the Keyblade Graveyard.

"Someone had to safeguard the light... from the demon I unleashed. You must know about the boy by now, the one in the mask. His name is Vanitas. A creature of pure darkness. One of my making."

- Xehanort explaining his actions to Terra.

"Vanitas is the darkness that was inside your friend. It was an accident. While training with me, Ventus succumbed to darkness, and there was but one way to save him—strip that part of him away. And thus Vanitas was made. In the process, I damaged Ventus's heart in the most horrific way. So I did what I felt was right, and left him with Eraqus. I knew the boy could not stay with me, the man who did him such grievous harm."

- Xehanort revealing Vanitas's origins to Terra.

"Ah yes. Well, I did my best to contain him the moment he emerged, but..."

- Xehanort discussing Vanitas with Terra.

"Vanitas uses the Keyblade to sow seeds of darkness. And now, you see—the worlds teem with his ghastly underlings."

- Xehanort revealing the origins of the Unversed to Terra.

"He has no control over the darkness in his heart. The Keyblade is not his to bear. He's an abomination beyond hope of salvation. Lend me your strength, Terra. Right this wrong that I have wrought."

- Xehanort feigning regret over the creation of Vanitas.

"What I can tell you about Vanitas amounts to this—his darkness is drawn to the light, which he seeks to disrupt... and then destroy. It stands to reason that he will strike next in the city of light, Radiant Garden."

- Xehanort advising Terra on where to find Vanitas.

"What are you doing, Terra?! Fight! Never mind me. You must fight! You can't let this ruffian win. Think of your Master, Eraqus—the shame he and your fellow pupils would be forced to bear! Use the Keyblade!"

- Xehanort manipulating Terra into fighting Braig.

"Well done, Terra. You have taken yet another step forward."

- Xehanort congratulating Terra on his victory against Braig.

"Then don't. You could be my pupil. Master Eraqus, you see, is so afraid of darkness, that he too, has succumbed—not to darkness, but to light. It shines so bright, he forgets that light begets darkness. And Aqua and Ventus, their lights shine too bright. It is only natural that they cast shadows on your heart. Eraqus... He is such a fool! Light and darkness, they are a balance—one that must always be maintained. Terra... you are the one who shows the true Mark of Mastery, but he refuses to see it. And I know why. It is because he fears you. Join me. You and I can do the worlds much greater good, by wielding light and darkness in equal shares."

- Xehanort trying to convince Terra to join him.

"See more worlds. Seek out the darkness that upsets the balance. Find Vanitas. And bring an end to him... Master Terra."

- Xehanort sending Terra on his way and naming him master.

"Unlikely. A powerful light still lives inside of Terra. You see, people like him... they don’t have the power to steal hearts."

- Xehanort conversing with Braig.

"We meet again, boy."

- Xehanort meeting Ventus at the Keyblade Graveyard.

"Ah yes, so you are starting to realize... what you lost—oh, but not for good. You had to lose in order to find. Now it can all be yours again, if you only reach out and take it. Reclaim the part that left you. Clash with him! Pure light against pure darkness, to forge the ultimate key. The all-powerful χ-blade!"

- Xehanort encouraging Ventus to remember Vanitas.

"Not the Keyblades you and I carry. "χ"... A most ancient letter. Some say "kye," but the meaning is the same. Death... A letter that spells endings."

- Xehanort explaining the χ-blade to Ventus.

"Eraqus knows it too. He knows exactly what you are. Haven't you ever wondered? Why he never granted you permission to leave his side, to grow stronger? Eraqus was frightened of you. If you were to learn the truth, realize what you are... He never trusted you. Why else would he keep you within his sight at all times?"

- Xehanort turning Ventus against Master Eraqus.

"Go! You can ask the man yourself. Learn the truth, and remember you have a greater purpose!"

- Xehanort sending Ventus into the Lanes Between.

"Master Terra. Find me. We must speak at once."

- Xehanort summoning Terra to the Keyblade Graveyard for the second time.

"There is no time to lose! I've terrible news. Ventus has stumbled upon the secrets of his origins."

- Xehanort explaining Ventus's emotional turmoil to Terra.

"Ventus is on his way home. If you could have seen the fury in his eyes... I'm certain he's capable of anything. I fear the boy may attempt to force the truth out of Eraqus. Master Terra, you must hurry back and see to your friend's safety."

- Xehanort sending Terra to battle Eraqus.

"What a sight. Why do you trouble yourself with remorse, Master Terra? The man was bent on doing harm to your friend, his own pupil!"

- Xehanort after killing Master Eraqus.

"You know, at times I find your progress quite striking. But you still fall short. Let all that anger out, my boy. Give your heart over to darkness!"

- Xehanort encouraging Terra's journey into darkness.

"Still so blind... Then I will make you see. Come to the place where all Keyblade wielders leave their mark on fate—the Keyblade Graveyard! There you will watch your dear Ventus and Aqua meet their ends, and the last light within you will die!"

- Xehanort encouraging Terra's journey into darkness.

"You won't need a home anymore where you're going!"

- Xehanort destroying the Land of Departure.

"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."

- Xehanort announcing his plan.

"Admirably done. I knew this was a journey you could make—over the unseen wall that divides darkness and light. And I was not wrong, Terra!"

- Xehanort congratulating Terra on his progress.

"Why, I did him a favor and freed the darkness inside him. Alas, poor Ventus never had the fortitude for such strenuous trials."

- Xehanort explaining his actions against Ventus.

"Go take what Ventus owes you. And take Aqua's life."

- Xehanort sending Vanitas away.

"You see how powerless you are to save them? Savor that rage and despair. Let it empower you!"

- Xehanort trying to get Terra to succumb to the darkness.

"Yes, boy, that's it! More! Let your whole heart blacken with anger!"

- Xehanort as Terra is overwhelmed by darkness.

"There, you see? The χ-blade has been forged! And now, Terra, it is time for the final union!"

- Xehanort upon the creation of the χ-blade.

"At last, our moment is here. Out with the old and brittle vessel, and in with a younger, stronger new one! I swore I would survive... and be there to see what awaited beyond the Keyblade War! And now it is your darkness that shall be the ark that sustains me!"

- Xehanort taking control of Terra's body.

"Darkness rules your heart—it gives me control. Muscle and sinew that once obeyed you now rebels against you. How you can remain here at all confounds the mind."

- Xehanort conversing with Terra inside the new Xehanort.

"Hmph. Don’t even entertain any notions of escaping me, boy. In the end, your heart will be engulfed by mine forever."

- Xehanort threatening Terra.

"As I recall, you couldn't even handle your own darkness. How, then, will you triumph over mine?"

- Xehanort insulting Terra.

"Oh? So that's how it is, is it? Someone else has set foot in your heart. Eraqus, you sly fox..."

- Xehanort discovering Eraqus has been in Terra's heart.

"Brave words, to be sure. But I'm a patient man. We can take as much time as we need to settle this little property dispute. However, know this— You are just one of many roads that I might choose to take. Trust me. I made certain of that."

- Xehanort revealing his intentions.

"I said, hands off!"

- Xehanort after possessing his younger self and overriding Mickey's Stopza.

"All of this was decided. My twelve selves would welcome me here on this day, when I would return a complete person. It is the future that lies beyond my sight."

- Xehanort upon taking his place in the real Organization XIII.

"In ancient times, people believed that light was a gift from an unseen land by the name of Kingdom Hearts. But Kingdom Hearts was safeguard by its counterpart, the χ-blade. Warriors vied for that precious light, thus beginning the "Keyblade War." The violent clash shattered the χ-blade into twenty pieces— seven of light, and thirteen of darkness. And the only real Kingdom Hearts was swallowed by the darkness, never to surface again."

- Xehanort telling the story of the Keyblade War.

"I once tried to create my own pure light and darkness to forge the χ-blade, but the attempt ended in failure. In my eagerness, I had lost sight of the correct way to achieve my goal. I acted rashly. I can admit that now."

- Xehanort admitting his past mistakes.

"Ah, but destiny is never left to chance. I merely guided them to their proper places. The broken boy who failed to be the blade... the misguided master who sacrificed herself for a friend... and the feckless youth who became my new vessel."

- Xehanort responding to Mickey's accusations over changing the destinies of Ventus, Aqua and Terra.

"Yes. They were all my doing. I used the evil fairy to find seven pure lights for me, just as I prepared thirteen vessels to fill with pure darkness."

- Xehanort explaining about him secretly using Maleficent to collect 7 hearts of light for him.

"Yes, he did. That dull, ordinary boy— a Keyblade wielder so unlike any I have ever seen. However, I have not abandoned my ambitions— the seven guardians of light and the thirteen seekers of darkness."

- Xehanort in response to Riku's claims about Sora.

"Yes, little king. Perceptive. But Sora and another on your list belong to me now. And that puts you three guardians short. But worry not. All of the pieces are destined to appear. Your seven lights just like my thirteen darknesses, whose final clash will beget the prize I seek— The χ-blade! But first, the thirteen darknesses shall be united. All the seats have been filled. And now the last vessel shall bear my heart like the rest!"

- Xehanort beginning to turn Sora into the thirteenth vessel.

"Freeze!"

- Xehanort launching an ice spell that has the ability to freeze Terra.

"Thunder!"

- Xehanort initiating a powerful overhead thunder spell.

"Concede!"

- Xehanort causing a huge piece of land to rise under Terra.

"Feel the darkness!"

- Xehanort summoning a number of Keyblades in a flowing spiral.

"Taste defeat!"

- Xehanort summoning a number of Keyblades in a flowing spiral.

"You played your role admirably!"

- Xehanort holding Terra while trying to freeze him.

"Now accept your reward!"

- Xehanort holding Terra while trying to freeze him.

"You are weak!"

- Xehanort striking Terra with his freeze spell.

"Fool!"

- Xehanort striking Terra with his freeze spell.

"Only now, have I truly won."

- Xehanort upon defeat.

"I could die of laughter!"

- Xehanort upon victory, in the Game Over screen.

"Is that really all the strength you can muster?"

- Xehanort upon victory, in the Game Over screen.

Trivia

 * According to Nomura, Kingdom Hearts III will be the last game where Xehanort is the villain.
 * It is unknown who will voice Xehanort in Kingdom Hearts III, as both his Japanese and English voice actors have since passed away.
 * Master Xehanort is the overarching and most recurring antagonist in the series, as every incarnation is the main antagonist in each game: Xehanort himself is the main antagonist in Birth by Sleep and Kingdom Hearts III. Ansem, Seeker of Darkness is his Heartless, and he is the main antagonist in Kingdom Hearts. Xemnas is his host body's Nobody and the main antagonist in Kingdom Hearts II. Young Xehanort is his teenage self and the central antagonist in Dream Drop Distance.