Well, I could lie and tell you what I am, when I'm actually a brilliant artist, or even a scholar. I could tell you that I dream of world peace. When I'm actually planning it's destruction. The truth is what you see with your eyes, not what you hear.Master of Masters to Master Xehanort while in his younger days.
The true personality of the Master is unknown due to his contradicting manner in all his appearances. He constantly behaves in an unpredictable and eccentric manner despite his extraordinary intelligence and wisdom but his ability to stage the Keyblade War while ensuring the worlds would still exist, manipulating his own loyal apprentices with no apparent qualms despite their absolute loyalty and his apparent affection for them, indicates a machiavellian personality.
His true allegiance remains unknown as although he apparently cared enough for the existence of the worlds to ensure they would survive despite this not stopping him from carrying out his mysterious plans, he was willing to let several disastrous events unfold while merely watching. In addition, he is quite capable of being serious, as displayed by his ability to strike clear worry into his extremely powerful apprentices when they asked him regarding their roles, despite often returning to his old self.
His talks with Luxu and Xehanort reveal more of his true feelings. He is shown to be cynical over the current state of the world and supports Xehanort's view that the current state of the world has the weak steal power from the strong and unjustly claim it was righteous and that such hearts would only give birth to more darkness, while also stating he believes that what is right is not what is heard but what is seen. He seeks to end the fight with the darkness once and for all and defeat it for good but his previous experiences fighting the darkness and losing many if not all of his comrades has left him hardened and bitter and willing to do whatever it takes without having his heart clouded by feelings. He himself freely admits that what he is doing is not heroic despite his apparent good intentions, showing he is fully aware that his plans would cause a great deal of suffering and destruction and while appearing callous about it, is more of somberly resigned to opposition. His first plan to end the conflict by ending the Keyblade War and ending the world to then recreate it was to defeat the conscious beings of Darkness and plant the seeds of light for the future generation to defeat the darkness and he went along with it while using his apprentices to ensure the success of his plans.
The Master of Masters himself firmly stands against the Darkness to where he expresses clear shock that Luxu would compare Darkness to himself and considered the entity that refers to itself as Darkness as being his complete opposite, despite Darkness referring to the Master as an old friend, showing that the Master ultimately remains inclined to the light, even if he is willing to let darkness rampage. While conversing with Darkness, he keeps a polite tone but also makes his stance against it clear as he specifically stated that he ended the original world to recreate it to a better one with future generations of light capable of defeating the forces of darkness and also stated that he would have never let Darkness read the Book of Prophecies had it contained knowledge of everything.
The Master of Masters appears as a person completely concealed in a black coat. Nothing else is known about the Master's appearance beneath the hood, although according to Chirithy he has an eye that gazes into the future. As the Master has installed one of his eyes inside the Gazing Eye, he has seemingly lost one of his eyes, although it remains unknown if he can't just regenerate or replace it.
Before Kingdom Hearts χ
When the Master of Masters was just a boy, the Keyblade War had already began between light and darkness. There were other Keyblade wielders at that time and he stated that he had many comrades and loved ones but he didn't have a Master of his own despite being a Keyblade Master, meaning he created the title himself. During the battle with the darkness, it took the form similar to, but not quite, that of a human. In time, the Master of Masters lost many of his comrades as darkness overtook their hearts.
Years later, the Master of Masters, having studied the χ-blade, used the skills he learned from it to take in six apprentices, Luxu, Ira, Ava, Invi, Aced and Gula, and began to train them into becoming Keyblade Masters of their own right, giving them Keyblades crafted from their own hearts and their names. The Master of Masters also created the Book of Prophecies with his Gazing Eye to view any events in the future it witnesses and copied it multiple times so all his apprentices except Luxu could have their own Book of Prophecies. The Master of Masters also devised a sophisticated plan to end the darkness once and for all by training his apprentices so they along with himself can lock away the seven strongest beings of darkness that would be defeated when they were sent away by the future generations of light that would be born in the future and then ending Keyblade War by temporarily destroying the world but leaving the Dandelions to recreate the world upon leaving the data world.
He first bestows Luxu the Gazing Eye and instructs him to pass it on to others so that the Gazing Eye can relay future events to him and he can write the Book of Prophecies successfully. He then orders Luxu to watch and if necessary interfere as things happen between his fellow apprentices and also gives him the Black Box, which he decides to tell Luxu about at the condition he swear not to tell anyone else, with the contents being indicated to be a copy of the Book of Prophecies despite him not giving Luxu one to prevent him from causing paradoxes but whatever it was caused Luxu great surprise, which the Master simply said that he'll see sinisterly. They would frequently convene at the Control Room of the Data Daybreak Town, revealing the truth of the Keyblade War and the existence of Darkness, as an entity, to his apprentice as well as his reasons to have Ava gather wielders with a particular aversion to Darkness become Unchained and travel to the world outside, where they'd gather light from the scattered worlds to rebuild the one destroyed by the Keyblade War. Appeasing Luxu's concerns over both the Dandelions and the seeming imposibility to defeat the Darkness, the Master of Masters reveals he has a plan capable of defeating Darkness once and for all but it is complex and will take several lifetimes to realize, revealing that he had spoken to Darkness several times, though neither of them got through to the other due to their unconventional views. He grants Luxu permission to watch over the Dandelions as long as he doesn't interfere. In their final conversation, the Master explains that when the Lifeboat he created departs the world will end and those left behind will sink into slumber and reveals his grand plan: Darkness has cast away its form in order to attack people's hearts, but in doing so, its will begins to fade and there are thirteen Darknesses, and they could be destroyed once they attained physical form. This is why that he had raised his apprentices so that their hearts would be strong enough to lock away the seven strongest iterations of Darkness and ensure that the future generations of Light would defeat them wherever they landed, while five of the remaining six would be locked within the Union leaders, leaving the last to be caged within Data-Daybreak Town. This left Luxu horrified and embittered at the Master's willingness to sacrifice so many and as Luxu left without saying another word, the Master solemnly recounted on how he had knew from the beginning Luxu was the traitor and counted on his alterations.
After Luxu leaves, the Master of Masters then proceeds to reveal that he will disappear and makes Ira leader of the Foretellers to keep his other apprentices in check, but rebukes Ira's desire to prevent the final battle of the Keyblade War he had planned, stating it was inevitable. He then makes Aced Ira's right-hand man, with the task of taking charge should Ira prove to slack in his task, accounting in Aced's react personality to push Ira into action but considering his true intentions, and Invi the moderator, tasked with keeping watch over the others and reporting to Ira if the others tried to disobey his teachings, with the likely intention to delay the Keyblade War until Ava's task, to gather all the exceptional Keyblade wielders he chose from every union to form the Dandelions and train them to venture out of the destroyed world to ensure the survival of the light and recreation of the world.
Gula's task to stop the traitor in the Lost Page was clearly a set-up mission to make Gula gather the Lux needed to summon Kingdom Hearts, knowing the others will have to counter him by gathering as many Lux as possible. Finally, he creates the Chirithy to aid Keyblade wielders, with a warning to his apprentices that if the wielder falls to darkness, their Chirithy will be corrupted and become a Nightmare.
With all his plans done, the Master of Masters then carries out his plan and vanishes into Quadratum to ensure no one would be able to find him, leaving so little traces that the Foretellers, despite their search, are unable to find the Master.
After helping Chirithy fend off the Minute Bombs in Daybreak Town, the Player goes to sleep. They have a dream in which the five Foretellers converse with their master before the Player has a chance to approach the Foretellers and their mysterious visitor, they are engulfed in darkness and wake up.
The Master of Masters is mentioned by the Secret Reports written by Luxu. It was stated that out of the five new Union leaders, there is one he didn't chose. Luxu also lamented that without the Master, the darkness began to spread even without any Keyblade War. It has been stated that the Master will return after the Keyblade War comes to a close and the Foretellers are reunited with Luxu.
The Master of Masters is seen in the secret movie Yozora. As he stands atop a building, he uses his hands to make an outline of Kingdom Hearts with the distant moon.
Master Xehanort told Xigbar and Saïx that about seventy-five years ago, he had met the Master of Masters at the Keyblade Graveyard, and how the latter would have given him his Black Coat with which to repel Darkness while browsing the different Worlds. Xehanort tells the Master that all the "Corruption" he had seen through the many Worlds he had visited had made him lose his faith in Humanity. Determined to put Order into this Chaos, he decides that it would be necessary to "remake the Worlds". He says his decision will become clear after his next Mark of Mastery Exam, but the Master of Masters tells Xehanort that the results don't matter if one has already made his decision. He says that soon Xehanort will no longer need his Black Coat, as it will be powerful enough to control the Darkness without it. Xehanort asks if he is a fortune teller, but Master of Masters will only make numerous claims about his identity before telling Xehanort his name, proving to be one of the "Lost Masters".
Currently, nothing is known about the Master's might but he is certainly an extraordinarily skilled and powerful Keyblade Master, having personally trained the incredibly strong and skilled Foretellers and Luxu, molding them into powerful Keyblade Masters themselves, while still being superior to their level of might, deemed by Gula as having the power to forcibly stop all of them from causing the Keyblade War. All the Foretellers have shown absolute respect of his strength and even fear of his power, able to effortlessly intimidate even the arrogant and powerful Aced merely pretending to find his disapproval of Ira becoming the leader undesirable. He is at least strong enough to casually move the heavy Black Box from a kneeling position even without aid from Luxu. The Master has also indicated that he is stronger than the being who calls itself Darkness, who he himself acknowledged to be a difficult opponent even for the likes of the combined might of the Dandelions, exceptional Keyblade wielders in their own right, as he stated that Darkness is wary of him and would prefer to avoid a fight with him.
Being perhaps the oldest character alive in the series, the Master has extraordinary knowledge and in addition to foretelling and writing the future in the Book of Prophecies, he also proved able to write detailed notes about many topics such as the Keyblade and Heartless. From his study of the χ-blade, the Master has the ability to create Keyblades from the hearts of others and can also seemingly construct Keyblades of his own without needing to use the hearts of others, as he was able to create the Gazing Eye, which was not his main Keyblade, through unknown means. The Master also appears to be extremely skilled in sorcery, capable of many powerful enhancements, displaying a commendable level of mastery over time-based magic, having been able to enchant the Gazing Eye within the No Name Keyblade he gave Luxu so from it he could perceive anything the Eye saw from anywhere throughout time, which made the Book of Prophecies he authored possible to exist, and he also seemingly enhanced the Book with the power to summon powers from the future. The trap set in the flow of time to prevent any attempts to rewrite the past and trapping those who tried inside a data simulation of their world created by him may also be another piece of the Master's magic. He also invented the Lifeboat that is capable of allowing time-travel to the future at the cost of losing their body and he even managed to come up with a way to travel into the future by using the memories of Luxu and his eyes as a medium as well as using the Book of Prophecies as waypoints and he also could somehow allow Luxu to time-travel, stating that he is not bound by either the boundaries of time or the worlds, suggesting that he, like Merlin and Yen Sid, has the ability to circuvment the normal rules of time travel and he definitely has the ability to travel between worlds through unknown means, as Luxu stated that the Master already had the means to escape the world's destruction. The Master also appears to be highly proficient in manipulating light and darkness, being capable of creating the Spirit Chirithys for the Foretellers and their Union members, creatures capable of wielding powers of light and also becoming corrupted and controlling creatures of darkness, and also creating bangles capable of siphoning and harnessing dark energy. When conversing with Luxu, the Master dimmed the light of the lamp and then lit it back up by just pointing and swinging his hand at the lamp. In another conversation with Luxu, by just spreading his arms open, he was able to surround them with pitch-black darkness and remove it at whim, also displaying the ability to influence technology, shutting down the computers of the room, which he did without needing any additional gesture, and teleport, instantly appearing behind Luxu's back as soon as he restored the light. He also displays the ability to warp reality to create realistic projections, surrounding himself and Luxu with an illusion of Dive To The Heart and generating images of the Foretellers and having them circle around without actually teleporting them into the Dive To The Heart. The Master appears to be capable of sensing whenever Kingdom Hearts is summoned, as his apprentices believe that summoning Kingdom Hearts would cause his return. Through unknown means, he was able to remain alive through the centuries after the Keyblade War with seemingly no deterioration to his vitality and power, indicating he is either immortal or used the same heart-extraction technique Luxu used to remove his heart from his body and then possess another body. The Master even confidently stated that he could fulfill his plans of defeating the darkness, which he himself stated would take longer than two lifetimes, further enhancing the possibility of him being immortal. He also reveals that he had been able to train and strengthen the Foretellers and Luxu's hearts so that they couldn't be possessed by the 7 strongest forms of Darkness and he himself also could safely keep one in his own heart and was able to somehow eject them when the time came so they would be defeated when they landed, showing the Master's heart is enormously powerful and he is also well-versed in the manipulation and empowerment of the heart. The Master of Masters even discovered the world of fiction Quadratum, knowing of it's nature that effectively meant no light or darkness can reach it, and had the ability to reach it and somehow return to the real world and back to Quadratum, as displayed by his ability to visit Xehanort and then remain there.
An extremely intelligent and wise man, the Master of Masters is an extraordinary strategist and manipulator, as he gave each of the Foretellers their own roles specifically based on his knowledge of how they would react to successfully ensure the Keyblade War would occur and despite the overwhelming darkness unleashed from the war, he was still able to successfully keep the light from fully expiring and prevent the darkness from completely consuming everything, allowing the worlds to exist, but separated, by having the members of the Dandelions transported to a different worldline so as to protect them and their light.
Along with that, he also successfully instructed Luxu in how to enact another Keyblade War that was so magnificently done that Luxu successfully eluded all detection in his part, to the point that even the brilliant Master Xehanort was completely fooled into believing Luxu, as Xigbar, was merely desiring the power of the Keyblade enough to join him.
Although the main Keyblade of the Master of Masters is unknown, he created and briefly wielded The Gazing Eye, a Keyblade forged from one of his eyes, which he used to see future events in order to write the Book of Prophecies.