Aizen is a tall, mild-featured man with short brown hair that is sweeped back with a single strand to hang down in front of his eyes, and matching brown, menacing eyes. Following his rebellion of Soul Society, Aizen wears a white vest, and on top of this, a white long, long-sleeved robe, reminiscent of his old captain's haori, with an extended collar and no insignia on the back, as well as a pink sash around his waist, white hakama, black tabi, and white zori.
Aizen is a polite, soft-spoken intellectual, often addressing his subordinates by their given names. He rarely shows any sign of alarm or distress, and often has entire situations planned out well in advance. Whenever confronted, Aizen is casual and uncaring, attempting to draw out a conversation and make small talk, which often infuriates those he is talking to.
Aizen initially appeared to be a very kind, well-respected captain and was looked up to by many, especially his lieutenant, Momo Hinamori. However, this was just a mask to disguise his manipulative, corrupt, calculating, cruel, and very dangerous, nature. In truth, he cares very little for his underlings, and is willing to use almost everyone around him as pawns to achieve his goals. He is willing to stop at nothing to further his selfish ambitions, including manipulating or killing anyone if he deems it to be necessary, showing his more cold-hearted and callous nature. He frequently toys with his underlings for amusement, and states that he doesn’t have any morals, saying they just restrict his capabilities.
During his time as a Captain, Aizen liked tofu, but he disliked boiled eggs. In his free time, he often read, and he gave a special lecture of calligraphy at the Shinigami Academy because he excelled in this branch of arts. This optional course was immensely popular among the Shinigami students, and many of them felt great sorrow at Aizen's sudden departure.
As the commander of his army of Arrancar, Aizen controls his minions through acquired respect or fear. Ulquiorra Cifer revealed to Orihime Inoue that they are all there to further Aizen's ambitions. Aizen keeps more rowdy individuals like Grimmjow Jaegerjaquez in line through intimidation and mind games. The Arrancar, Aisslinger Wernarr claims the Arrancar follow him because he has no fear, something which beings born from fear and despair find inspiring.
Gin Ichimaru has some sense of Aizen's emotions and feelings, correctly pointing out Aizen was enjoying the invasion by Ichigo and his friends and their successes within Las Noches, which Aizen himself confirmed, and noting Aizen was surprised by the arrival of Momo during the battle of Fake Karakura Town. In contrast, Kaname Tōsen has shown no such understanding, and has fallen victim to one of Aizen's more minor mind games when Aizen subtly manipulated him into punishing Grimmjow for him while Aizen himself kept up his appearance of benevolence.
Aizen's true objective was to overthrow the king of Soul Society. As he and his fellow traitor captains were departing from the Soul Society, he told 13th Division captain Jushiro Ukitake "no one has stood on the top of the world", not even the gods, but he aspires to "stand on the heavens and end the unbearable vacancy on the world's throne".
According to Kisuke Urahara, since mastering the Hōgyoku, Aizen has become less cautious in battle, for Aizen would not have allowed Urahara to use level 90 Kidō before he subdued the Hōgyoku. Aizen admits his new powers allow him to let his guard down. Due to this newfound power, Aizen has developed an arrogant and overconfident attitude, often not even thinking his attacks or defense through any longer like he used to, or even bothering to find out the effects of his opponents' and his own attacks. In his newest form, he has developed a severe superiority complex, believing he is now above both Shinigami and Hollows. Because of his superior attitude and high intelligence, Aizen is easily enraged when facing something or someone which he does not understand; for example, when witnessing Ichigo Kurosaki use Final Getsuga Tensho, Aizen becomes furious because he is unable to comprehend how a Human has surpassed him.
Genius Intellect: Arguably, the most fearsome trait of Aizen is his tremendous intellect. He is well-versed in the history, strategy, and tactics of Soul Society, and is privy to knowledge unknown to many, such as the existence of the Ōken, as well as the obscure method in which to create one. He has created several Hollows and Arrancar while avoiding arousing any suspicion from the majority of his fellow Shinigami. For over 110 years, he had been engaging in experiments which involved unique and highly dangerous manipulations of Reiryoku and Reishi, including experiments involving the Hollowfication of Shinigami, something which had never been done before. He has an innate knowledge of the Hōgyoku, rivaling that of its creator, Kisuke Urahara; he even knows how to destroy it. He figured out the true nature of Shinji Hirako's Shikai and deduced it produces an optical illusion, allowing him to counter its effect. He effectively deduces the true nature of the Hōgyoku via trial and error of the situations which revolve around it.
- Master Manipulator: Aizen has proven himself very crafty and a cunning man since his public betrayal of Soul Society. He can deceive and manipulate others around him in different ways for a variety of purposes. For years, he convinced everyone around him he was a kind-hearted man with the best intentions for Soul Society while performing horrific actions. He has a great talent for analyzing and observing everything in his presence, allowing him to understand a person's pattern of thinking and better manipulate them. He is a master strategist, formulating well thought out plans several steps ahead of others. These plans are incredibly involved and detailed, and are planned out with the long term in mind. His most well-known plan spans over 110 years, a great accomplishment which involved moving people around like pieces on a chessboard and making sure they played the role he had planned out for them. He is masterful when it comes to plans within plans, such as kidnapping Orihime, allowing him to use her abilities to extend the shelf life of the Hōgyoku, and, after the departure of Gin Ichimaru, Kaname Tōsen, and himself, trapping Ichigo Kurosaki, Yasutora Sado, Uryū Ishida, and four captains in Hueco Mundo, making it easier for him to accomplish the goal of his first plan: creating the Ōken and gaining access to the Royal Palace.
- Master Strategist and Tactician: Aizen is a beyond-able tactician, able to adjust his plans to almost any situation presented to him at a moment's notice. He is a master of psychological warfare, being the center of his entire battle strategy, being able to completely break down the will and resolve of his opponents, as well as provoking them to attack him prematurely, leaving openings in their form for Aizen to exploit and strike. He has also made it a personal goal of his to familiarize himself with the strengths, weaknesses, and mannerisms of his opponents, allowing him to devise elaborate strategies for defeating them.
Kidō Grandmaster: Aizen has great proficiency in using Kidō spells. He is skilled enough to use mid- to high-level Kidō without the use of their incantation; he used Hadō #90. Kurohitsugi, and even though he did not utter its incantation, it was sufficient enough to disable 7th Division Captain Sajin Komamura. He has used Bakudō #81. Dankū to block Hadō #88. Hiryū Gekizoku Shinten Raihō from Tessai Tsukabishi, who was captain of the Kidō Corps and logically the most proficient Kidō master in Soul Society at the time, while Aizen himself was only a lieutenant. He can produce powerful protection spells while in battle.
Master Swordsman Specialist: While the full extent of his prowess has yet to be known, he has demonstrated the ability to effortlessly fight back an opponent's Shikai or Bankai with his own blade still sealed. He has also demonstrated the ability to perform tremendously powerful and precise strikes, capable of striking through very sturdy targets, such as Renji's Shikai, Harribel's Hierro, and Komamura's Bankai. He was also able to easily cut down four captains (two which used their Bankai) and four Visored (with three being former captains of the Gotei 13) with ease.
Shunpo Master: He is perceived to be so fast that one cannot discern even being attacked by him until after it has taken place. Aizen can easily outmaneuver Ichigo's Bankai and Hollow Mask-enhanced speed, to the point where he could casually lay a hand on Ichigo's chest and still dodge a point-blank attack. Aizen can dodge simultaneous attacks at close range and evade Bankai-level techniques. Opponents commonly do not know his movements until after he has made them, and Aizen is skilled enough in his movements to evade at high speeds, even when being attacked from behind.
Hakuda Master: While preferring to finish his fights quickly with his Zanpakutō or Kidō, Aizen is a highly capable fighter unarmed as well. Repeatedly, Aizen has shown himself able to effortlessly catch his opponent's weapons barehanded. While fighting offensively, he has shown tremendous agility and dexterity, able to combine both sword and barehanded skills to simultaneously strike with his sword and kick opponents with great force.
Tremendous Spiritual Power: Even by captain standards, Aizen possesses a tremendous amount of Reiryoku. His level of spiritual energy is twice than that of an average captain. A hint of Aizen's level of Reiryoku is given when he turns Wonderweiss Margela into an Arrancar before activating the Hōgyoku; Aizen states in spite of its half-awakened state, the Hōgyoku can be fully activated when temporarily fusing with someone with twice as much spiritual power as an average captain-level Shinigami, referring to himself. He claims that he is more powerful than all of the ten Espada combined. After two years being sealed away in Muken, Aizen is considered to be far more powerful then he was before he was defeated by Ichigo Kurosaki. His Reiatsu is violet.
- Masterful Reiatsu Control: 2nd Division Lieutenant Marechiyo Ōmaeda stated Aizen's mere presence is monstrously overwhelming. The force of Aizen's Reiatsu is great enough to, without any visible effort from Aizen, bring Grimmjow Jaegerjaquez, the Sexta Espada, to his knees. He has stated it takes a lot for him not to "crush an ant" (referring to Renji) in his path. Aizen's Reiatsu is powerful enough to nullify abilities, such as when he negated Suì-Fēng's Nigeki Kessatsu. His mastery of his Reiatsu allows him to use it as a shield that can vaporize living beings within a few meters of Aizen's body. He can focus his Reiatsu to break through dense barriers that are permeated with Reishi.
Immense Strength: Despite the fact that Aizen is rather petite when compared to captains such as Sajin Komamura and Kenpachi Zaraki, he is actually an immensely strong individual. Aizen is strong enough to stop the blade of Ichigo's Bankai, Tensa Zangetsu, with just one index finger (albeit Ichigo was already battle-worn from fighting Byakuya Kuchiki) and almost cut him in half with a single swing of his sword. He stopped 6th Division Lieutenant Renji Abarai's Shikai with his bare hand and broke it with one swing, injuring Renji in the process. He stopped Komamura's Shikai with his bare hand, proving his strength is more than enough to combat someone of the same level. Aizen further displays his strength by cutting through the sword and wrist of Komamura's Bankai.
Immortality: After being hit by Ichigo's Mugetsu, Aizen somewhat regenerates from the damage, though most of his new form's features have been destroyed and do not return. He is later confirmed by Central 46 to having been left immortal by his interaction with the Hogyoku.
Kyōka Suigetsu (Moon Mirror, Water Flower): In it's sealed form, it resembles a normal katana. The only decoration is the cross-guard, which is shaped like a hexagon instead of a rectangle. The two sides parallel to the blade are long, whereas the four sides above and below the blade are shortened, making it into almost a diamond or prism-like shape. It has a green handle and a white sheath.
- Shikai: The Shikai release command is "Shatter".
Shikai Special Ability: The special ability of Kyōka Suigetsu is Kanzen Saimin (Complete Hypnosis). It controls the five senses to the point that it can make the target misinterpret another person's form, shape, mass, feel and smell to be that of the enemy. The initiation condition for the hypnosis is to show the enemy the release of Kyōka Suigetsu. After seeing it just once, that person will completely succumb to the hypnosis. After that, every time it is released, that person will become Aizen's unwilling slave. Since the spell works when you see the ritual, those who can not see are consequently immune to the hypnosis. When he turns off the hypnosis by force of will, the image shown melts away/shatters. Kyōka Suigetsu's Complete Hypnosis is absolutely flawless; even if the target is aware that they are under the hypnosis, they cannot resist its influence. Kyōka Suigetsu's hypnotic abilities make it a highly useful tool in combat, as Aizen can quickly create simple or complex illusions to deceive opponents. By creating a decoy of himself, or other illusions to distract his opponents, Aizen can hide his own movements and attack with impunity; his opponent, meanwhile, will remain focused on the illusion until it's too late to react.
While the illusions Kyōka Suigetsu creates are quite powerful, those with considerable power and skill themselves may be able to note slight differences in the illusions compared to the real thing, even if they are not able to determine what, precisely, is different. Captain Retsu Unohana was able to detect something was amiss with Aizen's fake corpse, even though she did not realize what until seeing Aizen alive. This is how Aizen has deceived many people and killed them, including one of his own allies, the Tercera Espada, Tier Harribel. Gin reveals that the sole way to escape Kyōka Suigetsu's ability is by touching the blade itself before complete hypnosis is activated.
First Fusion: Aizen embeds the Hōgyoku into the center of his chest, which enhances his abilities.
- Protective Regeneration: By embedding the Hōgyoku into his chest, it has been demonstrated to actively protect Aizen by healing his injuries almost instantly. Aizen was able to take a point-blank level 96 destruction spell and escape only suffering slight burns. Immediately following that, he took a point-blank Hollow mask-enhanced Black Getsuga Tenshō and survived the attack. He can come out unfazed after being hurled into several buildings.
- Strength Augmentation: Aizen's already considerable strength is further enhanced by the Hōgyoku's evolution of his body. He is able to easily strike through a target's flesh with a single nonchalant sweep of his bare hands.
- Durability Augmentation: Aizen's durability is further enhanced by the Hogyoku's evolution of his body. Because of this, he can withstand Hado #91. Senjū Kōten Taihō without suffering any damage.
Second Fusion: After Urahara attempts to block the Reiatsu vents in his wrists with a seal, Aizen emerges from the resulting explosion unscathed as a phantom-like figure. His face is covered with a white canvas and his outfit is now a white cloak that is split in four sections near his waist. There is a cross in the middle of the cloak, showing where the Hōgyoku is embedded in him. After a short struggle with Yoruichi Shihōin, his Zanpakutō becomes fused to his arm. Also, when he is attacked, his body appears to crack and fold under damage, only actually bleeding when an attack is powerful enough.
- Enhanced Strength: Aizen created a shockwave after being knocked down by Yoruichi. This shockwave was fast and strong enough to catch even Yoruichi off guard, and subsequently destroyed the Anti-Hierro armor on her left leg. He also deflected a Bankai- and Hollow Mask-enhanced Getsuga Tenshō with a mere flick of his wrist.
- Enhanced Speed: Aizen's newfound power enhances his speed to the point where even captain-level opponents cannot register his movements. He caught Yoruichi off guard with his speed. He can incapacitate three captain-level opponents seemingly instantaneously.
- Enhanced Durability: His durability is great enough to block Isshin's Zanpakutō with just his foot and withstand a massive punch from an armored Yoruichi.
- Enhanced Endurance: Aizen performs in battle as if he were unharmed, even while taking severe damage. He withstands Isshin's point-blank Getsuga Tenshō and remains unfazed by the attack, despite having a bleeding gash on his forehead.
- Regeneration: Aizen demonstrates a form of regeneration, as seen when he recovers from Yoruichi's first attack.
- Enhanced Spiritual Power: After Aizen fuses with the Hōgyoku, both Shinigami and Humans are incapable of sensing his reiatsu, unless he voluntarily lowers his level and allows them to interfere. He compares this to how a two-dimensional being is incapable of interfering with a three-dimensional one. Isshin Kurosaki surmised that Aizen's spiritual power can only be sensed by someone that is at the same level as him.
Third Fusion: After completing his "chrysalis" stage, Aizen sheds his sleek phantom-like form to reveal a form similar to his original one, with the addition of long hair and gray eyes with purple sclera.
- Enhanced Durability: Aizen's durability has been further enhanced. He willingly lets the Kototsu collide with him, destroying it, while remaining unharmed. He also withstood a Bankai- and Hollow mask-enhanced Miegetsu with only sustaining little to no injury at all.
- Enhanced Spiritual Power: Aizen's already enormous Reiryoku is further enhanced. Aizen causes a Human soul to collapse and fade away by standing a few feet away from it. By his own claim, if Don Kanonji had come into contact with Aizen, the former would have ceased to exist. When Aizen touched Gin Ichimaru's arm, his Reiryoku caused the area touched to dissolve.
Reiatsu Concealing Cloak:
Hollow Research & Development:
- Gin Ichimaru (Subordinate)
- Kaname Tōsen (Subordinate)
- The Arrancars
- The Espada
- Ichigo Kurosaki (Arch-enemy)
- Kisuke Urahara
- Isshin Kurosaki
- Yoruichi Shihōin
- Gotei 13 Captains
- Gotei 13 Lieutentants
- Thirteen Court Guard Squad Seated Officers
- The Visored
- Uryū Ishida
- Yasutora Sado
- Orihime Inoue
Background in Other MediaEdit
- There is no escape within my Kyōka Suigetsu!
- You are nothing to me in terms of power! 'Cause you don't know the true meaning of it!