Aizen

Biodata

Power Progression

Background

Aizen was the son of Fumiyama and Seirin Aizen, both Fifth Division officers. Seirin died in a twenty-person rescue team sent to Hueco Mundo; none of the team survived. Aizen came to resent a system that sent Soul Reapers on expeditions with a reported fifty percent death rate 11.

At Shin’ō Academy, Aizen held an awakening record for thirty-five years before Jun broke it. He told Jun that losing the record relieved him of a burden 7. After graduation, he became the Fifth Division’s seventy-second seat and returned to the academy as a swordsmanship instructor. His father arranged teaching and World of the Living assignments that kept him relatively safe 13 14.

Fumiyama later died of old age. Jun observed that Aizen had grown colder after the loss; by the time Jun next learned of his position, Aizen had become sixth seat 97 98.

Appearance

Aizen appeared youthful, with a gentle smile and refined manner when Jun first met him 7.

• During his Hōgyoku fusion, his eyes became black with golden pupils 217.
• In his Fourth Form, his eyes became entirely luminous, six wings of light grew from his back, and a slit appeared on his forehead 219.

Personality

Aizen presents himself with courtesy and warmth while concealing his strength and intentions. Jun initially found his conduct reassuring, even though he recognized Aizen as dangerous. Both men guarded their secrets and learned to retreat when their conversations approached a boundary 7 11.

His anger at Soul Society grew from its treatment of ordinary Soul Reapers and their families. Like Jun, he wanted to overturn its class system, but he chose secrecy, manipulation, and the accumulation of power to achieve his goal 11 257.

Aizen could also treat people as pieces in his plans. When he asked whether Kōga Tatara was a “cog” in Jun’s scheme, Jun realized how far Aizen’s thinking had shifted 47.

Abilities & Skills

Kyōka Suigetsu

Aizen’s Zanpakuto is an illusion-type weapon whose Shikai induces Complete Hypnosis. He concealed its nature behind a water-type explanation 77 153.

• Its hypnosis affects people who witness the Shikai’s release; Jun avoided it because he had never seen the release occur 158.
• Aizen used an illusion of his corpse to stage his death 158.
• By the battle with Yamamoto, he could use the Shikai without a fixed release command 217.
• Unohana’s combat instincts had advanced to a point where Kyōka Suigetsu could no longer completely deceive her 175.

Bankai: Kyōka Suigetsu: Dreamlike Empty Blossom

Aizen activated his Bankai during the battle at the Soul King Palace. The world appeared to shatter and reassemble, after which Jun and the others found themselves at the entrance to the Senkaimon 257 258.

• Aizen described it as a Bankai he could use only once 257.
• Afterward, he said his Sword Soul remained, but he and Jun both understood that he would never perform another Bankai 258.

Kidō and Reishi Control

Aizen’s exceptional control lets him force Reishi to move as he wishes. He guided Jun’s early Kidō training, and both could effectively abandon incantations 11 13.

• He used Kurohitsugi against Instructor Hanazawa, who reversed the attack and later healed Aizen’s injuries 34.
• He used coordinated Kidō and Kagyō signals with Jun against concealed attackers inside a Shishō Saemon barrier 31.
• He possessed space Kidō in this timeline, allowing him to travel between Soul Society and Hueco Mundo 124.

Spiritual Power Control

Aizen’s ability to make Spiritual Power obey his thoughts gives him resistance to some illusions and rule-based abilities 218.

• He could form Reiatsu directly despite Jun’s Seven Laws changing its structure 218.
• During a later battle at the Soul King Palace, he could compress Spiritual Power to reach Transcendent-Level Reiatsu intensity, but only after a considerable charge time 256.

Hōgyoku Evolution

Aizen studied the Hōgyoku and used Orihime’s power to test its effects. Although he treated it as insurance, he did not fully understand what merging with it would entail 192.

• In his Fourth Form, he survived the destruction of his previous body and overwhelmed Jun’s assembled allies 219.
• Transcendent-Level Aizen represented evolution; further evolution required a defeat to trigger it 237.

Relationships

• Jun Shimizu — Friend, ally, and eventual opponent. They shared grievances about Soul Society but pursued different methods; Jun later called Aizen his best friend 11 91 219 257.
• Seirin Aizen — Mother and former Fifth Division twenty-ninth seat. Her death on a rescue mission shaped Aizen’s resentment 11.
• Fumiyama Aizen — Father and Fifth Division officer who arranged safer assignments for him. His death left Aizen colder in Jun’s view 14 97.
• Gin Ichimaru — Hated Aizen for taking part of Rangiku’s soul and sought a way to kill him 91 153.
• Rangiku — Aizen took part of her soul when she was young, an act connected in Jun’s deductions to Aizen’s experiments 73 91.
• Orihime Inoue — Aizen used her Sōten Kisshun to test and control the Hōgyoku’s effects 192.
• Felix — Accompanied Aizen when he left Hueco Mundo to wander 221.

Story Role

Alliance with Jun

Aizen met Jun in the Journal Hall, where they became reading and Kidō practice partners 7 8. Later, they fought concealed attackers together during the Shishō Saemon crisis. Instructor Hanazawa ultimately sent them away from the battlefield with his Kidō notes 31 34.

Their alliance continued despite divergent goals. Jun later told Gin that Aizen’s soul experiments had killed more than twenty Soul Reapers and nearly a thousand Rukongai residents 91.

Hōgyoku and Rukia’s Execution

Aizen maneuvered Urahara into hiding a Hōgyoku inside Rukia, then staged his own death. Jun saw through the false corpse but pretended to grieve 158 168. Aizen’s ultimate plan was to obtain the Oken, replace the Soul King, and rule Soul Society from a position of overwhelming power 168.

On execution day, Aizen defeated Soul Society’s defenders, took the Hōgyoku from Rukia, and escaped 175. He later used Orihime’s abilities to test the Hōgyoku while keeping his full objectives concealed from almost everyone but Jun 192.

Battle and Aftermath

Aizen fought Jun and Yamamoto, fused with the Hōgyoku, and evolved again after Jun’s allies mounted a coordinated assault. In Hueco Mundo, he overwhelmed the assembled fighters before Ichigo confronted him 217 219 220.

After the battle, Aizen visited Jun’s Arrancar cultivation base. Deciding Hueco Mundo was not where he belonged, he took a map and left to travel with Felix 221. He later reunited with Jun at the Soul King Palace and used his one-use Bankai during the battle there 257 258.

Notable Quotes

“But not me. If you want me to join your side, you’ll have to surpass me in power.” 219

“There’s only one chance.” 257