At some point, Aizen saw the potential of Shuhei Hisagi, Momo Hinamori, Izuru Kira and Renji Abarai, and Aizen took the latter three into his division , while sending Shuhei to the 9th division under Tōsen. While Kira and Hinamori were obedient and loyal, becoming the lieutenants of the 3rd and 5th Divisions under Gin and Aizen , respectively, Renji proved to be too rebellious and was transferred to the 11th Division (and later to the 6th, where he too became a lieutenant). Aizen also continued his experiments on Soul Reaper/Hollow hybrids with his creations Metastacia and White playing a respective role in the life of Rukia Kuchiki and those of Isshin Shiba and Masaki Kurosaki. In the case of Isshin and Masaki, Aizen knew of Ichigo's existence that resulted from White's actions and considered the youth a being worth studying to the point of engineering the hardships he would face later in life. Personality 250px|Aizen (center), in his new clothing after his defection, alongside Gin (left) and Tōsen (right) . During his tenure as a Soul Reaper, Aizen created a public image of a bespectacled intellectual whose humility and warmth were equaled only by his dedication to the Thirteen Court Guard Squads. However, it eventually became apparent that this was a carefully crafted facade designed to draw suspicion away from his true, sinister nature. Tite Kubo stated in an interview that "part of Aizen's appeal is that he's mysterious", and for this reason he did not think it is a good idea to go too in-depth with the character. In truth, despite his apparent kindness, Aizen sees his subordinates as only pawns and warns them in advance not to trust him. By his own admission, he views morality and empathy as weaknesses which must be expunged in order to reach one's full potential as he is not above killing others to achieve his goals. During his ascent to Hueco Mundo, Aizen discards his guise by removing his glasses and sweeps a hand through his hair to reveal menacing eyes and a very different hairstyle. Telling Jūshirō Ukitake he intends to "end the unbearable vacancy on the world's throne", Aizen's agenda is revealed to be the assassination of the Soul King so he can become the new ruler of the Soul Society.Bleach manga; chapter 178, page 15. After fusing the Hōgyoku into himself, Aizen becomes overconfident to the point of believing him to be invincible. But when fighting Ichigo Kurosaki after he mastered the Final Getsuga Tensho, unnerved by a stronger foe, Aizen discards his calm nature and becomes crazed with rage. His arrogance ultimately led to his defeat at the hands of Ichigo, and his sealing by Urahara. As Ichigo later mentioned, there seemed be a hint of sadness in Aizen's reasoning and high level of power, and that his current condition by the time of his defeat may have been the Hōgyoku granting his subconscious desire. By the end of the series he becomes somewhat of a changed person, and voluntarily goes back to serve his sentence having a new outlook on life .
At some point, Aizen saw the potential of Shuhei Hisagi, Momo Hinamori, Izuru Kira and Renji Abarai, and Aizen took the latter three into his division . Aizen also continued his experiments on Soul Reaper/Hollow hybrids with his creations Metastacia and White playing a respective role in the life of Rukia Kuchiki and those of Isshin Shiba and Masaki Kurosaki. 250px|Aizen (center), in his new clothing after his defection, alongside Gin (left) and Tōsen (right) .
R
, while sending Shuhei to the 9th division under Tōsen. While Kira and Hinamori were obedient and loyal, becoming the lieutenants of the 3rd and 5th Divisions under Gin and Aizen , respectively, Renji proved to be too rebellious and was transferred to the 11th Division (and later to the 6th, where he too became a lieutenant). Aizen
. Aizen
D
In the case of Isshin and Masaki, Aizen knew of Ichigo's existence that resulted from White's actions and considered the youth a being worth studying to the point of engineering the hardships he would face later in life.
D
Personality
D
. During his tenure as a Soul Reaper, Aizen created a public image of a bespectacled intellectual whose humility and warmth were equaled only by his dedication to the Thirteen Court Guard Squads. However, it eventually became apparent that this was a carefully crafted facade designed to draw suspicion away from his true, sinister nature. Tite Kubo stated in an interview that "part of Aizen's appeal is that he's mysterious", and for this reason he did not think it is a good idea to go too in-depth with the character. In truth, despite his apparent kindness, Aizen sees his subordinates as only pawns and warns them in advance not to trust him. By his own admission, he views morality and empathy as weaknesses which must be expunged in order to reach one's full potential as he is not above killing others to achieve his goals.
D
During his ascent to Hueco Mundo, Aizen discards his guise by removing his glasses and sweeps a hand through his hair to reveal menacing eyes and a very different hairstyle. Telling Jūshirō Ukitake he intends to "end the unbearable vacancy on the world's throne", Aizen's agenda is revealed to be the assassination of the Soul King so he can become the new ruler of the Soul Society.Bleach manga; chapter 178, page 15. After fusing the Hōgyoku into himself, Aizen becomes overconfident to the point of believing him to be invincible. But when fighting Ichigo Kurosaki after he mastered the Final Getsuga Tensho, unnerved by a stronger foe, Aizen discards his calm nature and becomes crazed with rage. His arrogance ultimately led to his defeat at the hands of Ichigo, and his sealing by Urahara. As Ichigo later mentioned, there seemed be a hint of sadness in Aizen's reasoning and high level of power, and that his current condition by the time of his defeat may have been the Hōgyoku granting his subconscious desire. By the end of the series he becomes somewhat of a changed person, and voluntarily goes back to serve his sentence having a new outlook on life