Sosuke Aizen

Despite his villainous acts, Aizen is a surprisingly polite, soft-spoken intellectual. He often calls his subordinates by their first names.[5][6][7][8] He rarely expresses anxiety or pain. He often succeeds in carrying out his complex plans. When entering battle, Aizen acts relaxed and carefree, attempting to strike up small talk with his opponents, which often irritates them.[9][10][11][12]

Aizen appeared to be very kind, a respected captain, and admired by many, especially his lieutenant, Momo Hinamori.[13] However, this was merely a mask that hid his villainous and manipulative nature.[14] In truth, he cares little for his subordinates and uses them as pawns to achieve his plans. By his own admission, Aizen is not bound by any moral or ethical laws, as he views them as nothing more than obstacles to his potential. He will stop at nothing to manipulate people and, if necessary, kill them to fulfill his ambitions.[15][16] He often toyed with his subordinates for fun. Unlike most Shinigami and even some Espada members, Aizen has no sense of honor or pity.

Before leaving Soul Society, Aizen appeared to be a calm, intelligent man. He had brown hair, soft brown eyes, and rectangular-framed glasses. He wore a haori over the standard Shinigami uniform. During his departure to Hueco Mundo, he broke his glasses and slicked his hair back. One strand fell over his face. As he admitted to Renji Abarai, the Aizen everyone knew never existed, as demonstrated by the change in his style.

In Hueco Mundo, Aizen initially wore Arrancar attire over his Shinigami uniform.[3] After they kidnapped Orihime Inoue, he appears in full Arrancar-style attire, complete with a purple sash.[4]

After being implanted with the Hōgyoku, Aizen's appearance changes several times (see below). When he is defeated by Ichigo Kurosaki, he loses all of his physical changes and returns to his original state.

When he was a captain, he was known to have a fondness for tofu and a dislike for boiled eggs. He usually spent his free time reading, and he also gave lectures on calligraphy at the Shinigami Academy—he was a master of the art. This club was incredibly popular among the students, and many were saddened by Aizen's sudden departure.[19]

As the commander of his Arrancar army, Aizen controls his subordinates, inspiring either respect or fear. Ulquiorra Cifer states that they are all there to further Aizen's ambitions.[20] Aizen keeps more violent individuals, such as Grimmjow Jaegerjaquez, in check through intimidation or deception.[21][22] The Arrancar Aislinger Wernarr states that the Arrancar follow him because he has no fear, and this inspires "beings born from fear and pain."[23]

Gin Ichimaru is able to read Aizen's emotions and feelings to some extent, accurately determining that Aizen enjoyed Ichigo and his friends' invasion and their success in Las Noches, something Aizen confirmed himself,[24] and noting that Aizen was surprised by Momo's arrival during the battle in the fake Karakura Town.[25] Kaname Tōsen, however, did not show such understanding and, for example, fell victim to one of Aizen's subtle manipulations: he punished Grimmjow himself, while Aizen continued to display his benevolence, remaining clean-handed.[26]

Aizen's true goal was to overthrow the king of Soul Society. As he and his followers left Soul Society, he told the captain of the Thirteenth Division, Jushirō Ukitake, that "no one has ever stood on top of the world," not even the gods, but he sought to "stand in the heavens and end the unbearable emptiness of the world's throne."[27]

Despite Aizen's cold-bloodedness, lack of pity and moral standards, Ichigo suggests that deep down he felt lonely and wished for someone in this world who could understand and appreciate him. In his opinion, all this time Aizen was trying to find someone who could recognize his talent and strength, but he never succeeded. Countless searches only led to the fact that he, having lost any faith in the possibility of not being alone, decided to hide this dream from everyone and devote himself to achieving higher goals, sparing nothing and no one. But somewhere in the depths of his soul, despite all his aspirations, all his enormous power that distinguished him from others from birth, Aizen wanted only one thing - to become an ordinary Shinigami.

Aizen once became a member of the 5th Division under Captain Shinji Hirako.[34] He began researching the Hōgyoku even before Kisuke Urahara. To this end, he fed hundreds of Shinigami souls and Rukongai residents with spiritual power to his Hōgyoku. However, it was not satisfied.[35] Gin Ichimaru accidentally saw Aizen somewhere in Rukongai with three other Shinigami kneeling before him. One of the Shinigami hands Aizen the Hōgyoku, which he places in a vial. Aizen and his henchmen dump the unconscious Rangiku Matsumoto nearby.[36][37] Shinji eventually promoted Aizen to lieutenant so he could keep a closer eye on him.[38] However, this action by Shinji only served to further Aizen's plans.[39]