Sōsuke Aizen (Black Sun)

"The gaze into the sun." - Tite Kubo

Sōsuke Aizen (藍染 惣右介,Aizen Sōsuke) is the former captain of the 5th Division in the Gotei 13; he later leaves the Soul Society with his followers, Gin Ichimaru and Kaname Tōsen. His lieutenant was Momo Hinamori. He was the main antagonist from the start of the series to the conclusion of the Fake Karakura Town arc. After being defeated in Karakura Town by Ichigo Kurosaki and being imprisoned in the Avici prison by the Central 46, he's soon freed by Akuma Hakaishin and is restored his powers by him in exchange for joining his army. He becomes a Demon Lord and is Akuma's #1 advisor.

Appearence
In Hueco Mundo, Aizen is first seen wearing Arrancar clothes over his Shihakusho. Afterwards, but before his transformation, Aizen wore full clothing similar in style to the Arrancar.

Prior to his departure from the Soul Society, he appeared as a mild-featured man with brown scholarly hair enhanced by square glasses. He wore the standard Shinigami uniform with a captain's haori. However, during his ascent to Hueco Mundo, he removed his glasses and swept a hand through his hair, revealing menacing eyes and a very different hairstyle (swept back hair, with a strand hanging in his face). As he had previously revealed to Renji Abarai, the Aizen they all knew never existed and this would seem to be a visual representation of that claim.

Aizen's appearance changes again upon his initial defeat by Ichigo Kurosaki. Aizen loses all of the physical changes made by his transformation and returns to the physical form he had prior to transforming. The only visible signs of his change that is left is in his left eye which has a purple sclera and white iris and pupil.

After joining Akuma Hakaishin in his quest, he reverts back to his Hueco Mundo garbs, but they have Gold lines going down the edges. He also have handcuffs with broken chains on each of his wrist to signify his inprisonment. His hair is as messy as when he was a Shinigami and he has his old glasses but with silver rims on the edges. He uses his nice guy attitude around others to deceive them. Akuma states that the attitude is annoying and cruel and part of the reason that he was recruited.

Personality
He is surprisingly 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 the one 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 and very dangerous nature. In truth, he cares very little for his underlings (both past and present), and is willing to use almost everyone around him as pawns in his twisted game of chess. In his own words, Aizen claims to be unaffected by any form of morals or ethics as he views them as mere restrictions on his potential. He is, therefore, willing to stop at nothing to further his selfish ambitions, including manipulating or killing anyone if he deems it to be necessary. He is fond of long, complicated, and somewhat convoluted plots, and frequently appears to toy with his underlings for amusement. Unlike most of the other Shinigami who appear to have some kind of honor and kindness, including some Espada, Aizen lacks genuine compassion and honor.

During his time as a captain, he was known to like tofu, but he disliked boiled eggs. In his free time, he often read and he also gave a special lecture of calligraphy at the Shinō Academy, given that 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 new minions either through acquired respect or fear. Ulquiorra Cifer, one of his noticeably loyal subordinates, revealed in a conversation with Orihime Inoue that they are all here to further Aizen's ambitions. For more rowdy individuals like Grimmjow Jaegerjaquez, he keeps them in line through intimidation and mind games. The Arrancar Aisslinger Wernarr also claims that they follow Aizen because he has no fear, something which beings born from fear and despair find inspiring. Other Arrancar occasionally follow Aizen for reasons unique to themselves, such as Szayel Aporro Granz, who follows Aizen with the hopes that he will eradicate the world of all non-Hollows.

To date, the equally manipulative Gin Ichimaru is the only person who seems to be able to see through Aizen's manipulation. Ichimaru has also shown that he has some sense of Aizen's emotions and feelings, correctly identifying that Aizen was enjoying the invasion of Ichigo and his friends and their successes within Las Noches, as well as picking-up on the fact that Aizen had registered the arrival of Hinamori in battle of Fake Karakura Town and was surprised by it. By contrast, Kaname Tōsen has shown no such understanding and has fallen victim to one of Aizen's more minor mind games when Aizen off-handedly 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 the Soul Society. As he and his fellow traitor captains were departing from the Soul Society, he told Jūshirō Ukitake that "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". To do this, he needs the Ōken(王鍵,Royal Key), a tri-pronged golden key that opens a portal to the dimension in which the Spirit King resides. While the location of the key is known only to Captain-Commander Yamamoto, Aizen knows how the original was created and how to manufacture another. To do this, 100,000 souls need to be gathered together (which will kill all the entities used) and vaporize a significant portion of the area used in its forging. His sights are therefore set on Karakura Town, which has an unusually large concentration of spirit particles.

According to Kisuke Urahara, since mastering the Hōgyoku, Aizen has become less cautious in battle; noting that before he subdued the device Aizen would not have allowed him to use level 90 Kidō; Aizen admits that his new powers allow him to let his guard down. Also due to this newfound power, he has developed more of a seemingly arrogant and overconfident attitude, often not even thinking his attacks or defense through anymore 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 also 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 that he doesn't understand; for example, when witnessing Ichigo in his "Final" form, Aizen becomes furious because he is unable to comprehend how a human has surpassed him. When joining Akuma and his gang, he reverts to his nice guy persona with a hint of sarcasm for others. He still as manipulative as ever but only worse. He uses people and even other Demon Lords for his own and Akuma's purposes. It's because of this that some of the Togabito distrust and don't listen to him at times. Akuma, however, is the only exception because he's grateful for freeing him from the accursed prison and is willing to share his knowledger with him. Akuma view Aizen as a great asset to the group and decides that if anyone messes with him they'll be eliminated. He uses this to his advantage to get people to follow his demands without question.

Abilities & Powers
High Intellect: Arguably, the most fearsome trait of Sōsuke Aizen is his tremendous intellect. He is well-versed in the history, strategy, tactics of the Soul Society, and is privy to knowledge previously unknown to many, such as the knowledge of the existence of the Ōken, as well as the obscure method in which to make one. He has also created several Hollows and Arrancar while being able to avoid arousing any suspicion from the majority of his fellow Shinigami. For over 110 years, he had also been engaging in experiments that involved unique and highly dangerous manipulations of spirit energy and spirit particles, including experiments involving the Hollowfication of Shinigami, something that had never been done before. He has an innate knowledge of the Hōgyoku, rivaling that of its creator, Kisuke Urahara, even the extent required for him to destroy it. He is able to figure out Shinji Hirako's Shikai ability's true nature and then deduce that it produces an optical illusion, allowing him to counter its effect. He effectively deduces the true power of the Hōgyoku via trial and error of situations that revolve around it.

Master Manipulator: He has shown himself to be a very crafty and cunning man since his public betrayal of the Soul Society. The most noticeable trait is his ability to deceive and manipulate others around them in multiple manners. For years, he was effectively able to convince everyone around him that he was a kind-hearted man with the best intentions for the Soul Society, while performing horrific actions. He has a great talent for analyzing and observing everything in his presence, allowing him to quickly understand a person's pattern of thinking and better manipulate them. He is also a powerful strategist, capable of 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, making them seem slightly convoluted. His most well known plan spans over 110 years, a great accomplishment given that it required moving people around like pieces on a chessboard, as well as 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 to trap the Ryoka and 4 Captains after the departure of Gin, Tōsen and himself in Hueco Mundo, making it easier for him to accomplish the ends of his first plan, to create the  Ōken and gain access to the Royal Dimension.

Master Tactician: He has also shown himself as a powerful and flexible tactician, capable of adjusting seamlessly to any given combat situation, if not plan out events well in advance. He understands the strengths, weaknesses and mannerisms of his enemies and creates strategies to achieve victory; this includes modifying an Arrancar for the sole purpose of defeating Yamamoto, a Shinigami whose abilities surpass his own. Though it can be said that the majority of his tactics rely heavily on his Zanpakutō's special ability, there are few better tactics than manipulating all the senses of your opponents, making it easier for one to attack. Despite viewing his power as worlds beyond others, he is also shown to be highly cautious in battle, placing special protections on himself so as to leave no blind-spots.

Kidō Master: Aizen has a great mastery at using Kidō spells. He is skilled enough to use Kidō without the use of their incantation; he used the Black Coffin (ranked 90) spell, and even though he did not control it entirely (utilizing only a third of the spell's original strength), it was sufficient enough to disable fellow Captain Sajin Komamura.He has even used Dankū (ranked 81) spell to block another Kidō attack by Tessai Tsukabishi, who was Captain of the Kidō Corps and reasonably the most proficient Kidō master in the Soul Society at the time, while Aizen himself was only a lieutenant.

Immense Strength: He is powerful enough to stop Ichigo's Bankai 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 a sword, and stopped Renji's Shikai with his bare hand and broke it with one swing, injuring Renji in the process. He was also able to stop Komamura's Shikai with his bare hand, proving his strength was more than enough to combat someone of his same level. Aizen further shows his strength by being able to effortlessly cut through the sword and wrist of Komamura's Bankai.

Immense Spiritual Power: Even by captain-level standards, Aizen has shown to have tremendous spiritual energy. Marechiyo Ōmaeda commented that Aizen's very presence is monstrously overwhelming. A hint to his actual level of spirit power is given when he turns Wonderweiss Margela into an Arrancar; before activating the Hōgyoku, and states that despite its half-awakened state, it can be fully activated when temporarily fusing with someone with twice as much spiritual power as an average captain-level Shinigami (referring to himself). The force of Aizen's spiritual power is also great enough to, without any visible effort, bring the 6th Espada to his knees. He has commented that it takes a lot for him not to "crush an ant" (referring to Renji) in his path. He also claims that he is more powerful than all of the Espada. Aizen has shown that his reiatsu is powerful enough to nullify abilities, such as when he negated Suì-Fēng's Nigeki Kessatsu technique.

Master Swordsmanship 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 and Bankai with his own blade still sealed. He has also demonstrated the ability to perform tremendously powerful and precise strikes, capable of cutting through very sturdy targets, such as Renji's Shikai. He was also able to easily cut down four captains (two which used their Bankai) and four Visored (with three being former captains of Gotei 13) with ease.


 * Nadegiri (撫で斬り, "Clean Sweep" or "Killing Several with One Sword Sweep"): This basic technique allows for a precision cut of extreme force and speed, it can casually slice through large, multi-story high opponents protected by steel skin. The opponent can be killed with one swift slash so precise, that they aren't even aware of until after it has taken place.


 * Kamishini (神キラー, "God Killer" or "Cutting down God with a Single Slash"): By swinging the user's sword across, they can make a sweeping motion that cuts everything within 2 km of the user. The force behind this technique is great enough to defeat even Adjuchas-level Hollow with little effort.


 * Tsubame Gaeshi (燕返し, "Swallow Reversal" or "Turning Swallow Cut") : A technique that mimics the motion of a swallow's tail during flight as observed. This cut was reputedly so quick and precise that it could strike down a bird in mid-flight. There are no direct descriptions of the technique. Hence, the "Turning Swallow Cut" has been reconstructed as a technique involving striking downward from above and then instantly striking again in an upward motion from below. The strike's second phase could be from below toward the rear and then upward at an angle, like an eagle climbing again after swooping down on its prey.

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 is shown to easily outmaneuver Ichigo's Bankai and Hollow mask-enhanced speed to the point he could casually lay a hand on his chest and still dodge a point-blank attack. He is capable of effortlessly dodging simultaneous attacks at close range and the evasion of Bankai level techniques. He moves so fast that opponents commonly do not know his movements until after he has made them and is skilled enough in his movements to evade at high speeds even when being attacked from behind. It's questionable if he is as fast as Yoruichi Shihōin or Suì-Fēng, especially seeing as they both caught him before he was able to unsheathe his sword to engage in battle before his escape from the Soul Society.

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.

Inventions

 * Hōgyoku(崩玉,Crumbling Orb, Viz: "Breakdown Sphere""): Aizen has stated that he arrived at the conclusion of the Hōgyoku before Kisuke Urahara, however, it ended in failure In order to finalize the Hōgyoku, the souls of hundreds upon hundreds of Shinigami and hundreds and hundreds of Rukongai citizens who bore Shinigami potential needed to be sacrificed to it, but it still wasn't satisfied. According to the experimental data Kisuke Urahara's Hōgyoku was also incomplete. Therefore he decided to steal that Hōgyoku and present it to his own Produced as a result to Aizen's Hollowfication research, this Hōgyoku is what gave the Visored their Hollow powers. This process used seems to spread as some form of possible infection through wounds, that has the desired effects on souls with high-level spiritual energy as compared to souls with low-level spiritual energy, causing those infected great sickness and fatigue, until they vomit up a white liquid that forms the beginnings of their Hollow mask, which then proceeds to transform their bodies and warp their minds. Other than that all that is known is that the process is accelerated by aggressive emotions. The conclusive result makes a Shinigami into a primarily Hollow-like humanoid, which is a highly unstable transformation causing mindlessness and aggression.


 * Caja Negación(反膜の匪 (カハ・ネガシオン),kaha negashion; Spanish for "Negation Box," Japanese for "Anti-Membrane of Negation"): This cube, when used on a subject, traps them in an alternate dimension from which there is no escape; however, this assumes it's being used as intended. More powerful Arrancar, namely the Espada themselves, can escape, given enough time.

Zanpakutō
Kyōka Suigetsu(鏡花水月, Mirror Flower, Water Moon): In its sealed form, it resembles a normal katana. The only decoration is the tsuba, which is 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.


 * Shikai: The release command is "Shatter"(砕けろ,kudakero) and is used to both activate and deactivate it The name Kyōka Suigetsu hints at its illusionary properties; the moon reflected in water and a flower in a mirror are things that can be seen but not held. It is a Chinese saying for seeing and desiring something that is a dream that cannot be easily grasped in hand, teaching people about temptations.


 * Shikai Special Ability: Kyōka Suigetsu's Shikai ability is Kanzen Saimin(完全催眠, 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 fall under the thrall of the hypnosis. The hypnosis is apparently long-lasting, seeing as the Visored are still affected by Kyōka Suigetsu even though they were hypnotized at least 110 years ago. Since the spell works when you see the ritual, those who cannot 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 his opponents. For example, 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. Kyōka Suigetsu's reiatsu gives it away to those keen enough to sense its actual presence past the illusions created by its complete hypnosis. The sole way to escape Kyōka Suigetsu's ability is by touching the blade itself before complete hypnosis is activated.


 * Bankai: Not Revealed.

Story Arc
For Yuki's involvement in the original Bleach plot, please see Aizen.