Isshin Kurosaki, Kisuke Urahara, & Yoruichi Shihōin vs. Sōsuke Aizen

 is one of the last battles to take place in the Fake Karakura Town. The fight ends up showing the true power of the Hōgyoku and how its been involved in Sōsuke Aizen's plans.

Prelude
Following his confrontation with Captain-Commander Genryūsai Shigekuni Yamamoto, Sōsuke Aizen is immediately attacked by a masked Ichigo Kurosaki who uses a Getsuga Tenshō on him. Injured, Aizen blocks the rest of Ichigo's attacks stating he had missed his chance to kill him. When Ichigo points out Aizen's injury, it suddenly begins to heal itself. When Ichigo wonders if this is a form of high-speed regeneration, Aizen asserts that he wouldn't undergo mere Hollowfication. Aizen reveals that he has implanted the Hōgyoku into his own chest and its power is healing its master. Aizen then declares that Ichigo's Reiatsu has developed well, just as he had always planned. He affirms that all of his battles have contributed to his growth, shocking Ichigo by disclosing how the events took place exactly as he designed.

Ichigo demands to know what he means, but Aizen asks him not to yell before calmly explaining that once he realized that Ichigo had been the thing he'd been looking for, he'd decided to help him grow. Aizen reminds Ichigo of oddities he should have noticed as a Shinigami, informing him that he should have gotten stronger than this after blocking more of Ichigo's attacks. Ichigo declares that his words don't match his story back at Sōkyoku Hill, but Aizen inquires as to why Ichigo should believe him back then and not now. Aizen reveals that he was the one who'd sent Rukia Kuchiki to the World of the Living; that he'd equipped Lieutenant Renji Abarai with the ability to detect her Reiatsu; that he'd informed the lieutenants on his whereabouts; that he'd always known where the Hōgyoku had been for the last 100 years; and, crucially, that he'd known about Ichigo since the day he was born. Just as he was about to explain Ichigo's heritage, Isshin Kurosaki interrupts and tells Aizen that he's said too much.

Isshin headbutts a shocked Ichigo across town, where he clings to a building before being kicked off it by his father. Aizen informs Isshin that this was a smart move. Isshin goes to his son, knowing that he will have many questions, however, Ichigo kicks him and tells him that he knows when to keep quiet. Isshin can see the questions in Ichigo's eyes, but his son denies this, knowing that if his father didn't tell him everything then he was sure he had his own reasons for doing so. Isshin marvels at how his son now speaks quite competently and Ichigo thanks his father for punching him as he now feels more alive than before. Elsewhere, Aizen comments on how Isshin must have put up a strong barrier just as Gin Ichimaru shows up behind him. Gin lets Aizen know that he saw no opening or necessity to come to his aid up until this point. Ichigo and Isshin reappear then and Ichigo engages Gin in combat as his father takes on Aizen.

Battle
Aizen and Isshin clash before Isshin grins, surprising Aizen by flicking his finger, sending him through several buildings. Isshin continues to attack him, but Aizen evades the attack only for its force to destroy the rubble below them. Aizen dodges another blow and uses '''Hadō #63. Raikōhō''' in retaliation. After battling a while, Aizen's movements begin to slow and Isshin asks if he has reached his limit. Aizen agrees that he's reached his Shinigami limit, but that he will undergo a metamorphosis due to the Hōgyoku's will finally starting to understand his mind.

Aizen tells Isshin that the Hōgyoku has its own will and that he only realized this once becoming its master. He reveals that the true power of the Hōgyoku is to capture and materialize the desires of the hearts around it. Kisuke Urahara wanted to dissolve the barriers between Shinigami and Hollow, which caused the initial confusion regarding its true nature. Aizen then attributes the rare occurrences around Ichigo to the Hōgyoku; taking all of Rukia's power and the awakening of Orihime Inoue and Yasutora Sado's power. Aizen knew this and used the Hollowfication of the Visored's as an experiment to prove this before sending Rukia to Ichigo's side. He is interrupted by the clash between Gin and Ichigo.

Seeing Ichigo struggle, Isshin tries to talk to his son, who yells back that he should not get involved. Gin wonders if he interrupted Aizen's speech, but Aizen denies this to be the case as he was just about finished with it. The Hōgyoku's powers begin to envelope Aizen then, shocking both Ichigo and Isshin, who have no idea what's happening and begin arguing over the issue. Aizen declares that the Hōgyoku deserves its name before he is shot from behind by a newly arrived Urahara, whom he welcomes to the battlefield..

Urahara notes how they haven't met in a long time and marvels at Aizen's new form, but Aizen notes it's ugly as it's only midway through his evolution. Aizen states that he is subduing the Hōgyoku rather than fusing with it and that Urahara failed to master it in contrast to Aizen. Urahara agrees that in the past, this was true, causing Aizen to query if he is admitting defeat. Aizen then uses Shunpo and impales Urahara with his Zanpakutō. However, he has attacked a portable Gigai, which bursts as Urahara appears behind Aizen and uses '''Bakudō #61. Rikujōkōrō''' against his back. Aizen states that he didn't expect Urahara to use such a cheap trick against him, like he did in his battle with Yammy Llargo, and asks what he will do now that he's been bound. Urahara then uses '''Bakudō #63. Sajō Sabaku and Bakudō #79. Kuyō Shibari''' in swift succession, which binds Aizen further. Urahara then begins an incantation with Aizen asking whether he really thinks he'll let him use that Hadō spell, but Urahara tells him its too late as he initiates '''Hadō #91. Senjū Kōten Taihō'''.

As Urahara remarks that Aizen has become careless because of his new power, his opponent appears behind him, unharmed and agrees. Aizen wounds Urahara's right shoulder with his bare hand, explaining that with the Hōgyoku's power, he's allowed to be careless as he's now invincible. Urahara insists that the older version of himself wouldn't be letting him try his attacks on him one by one. Spiritual energy cuffs then appear on Aizen's wrists, trapping and shocking him. Urahara explains that it's a seal, sealing the Reiatsu flowing out of his own palms. He states that Aizen will now be blasted by his own Reiatsu as he is enveloped in a column of light.

Aizen is enveloped in light, however, Urahara warns the others that the battle is not yet over. Moments later, Aizen emerges in a new form, shocking everyone. Appearing among them, Aizen marvels at Urahara's strategy of using level-90 Kidō to distract him from Urahara's new technique to seal him, which would have worked had Aizen not already subdued the implanted Hōgyoku. He informs Urahara that the Hōgyoku he created was completely beyond his own comprehension. Urahara unsheathes his Zanpakutō as Isshin comes up behind Aizen, who tries to attack both of them at the same time. His attempt fails as they use their teamwork to block his attack and then entangle him in an awkward position. An armored Yoruichi Shihōin appears suddenly, stunning Aizen, attacking him from above with such force the surrounding area is destroyed. Urahara yells for her to move, which she does so, but not before Aizen recovers and destroys the armor on her left leg. With his new form cracked, Aizen inquires if this is all they have and they better make the next move because he plans on crushing them all one by one.

Aizen states that if this is the amount of hope they have left, then it is his duty to crush every one of them. He invites them to try something else as Urahara observes that they are in a bind, considering Aizen easily broke the armor he designed to counter Hierro. Yoruichi takes this offensively, thinking he was criticizing her focus, which he denies, but she states that they broke because they were badly put together. Aizen disagrees stating they were special considering her leg is fine. Isshin watches his comrades bicker some more as Aizen states that, regardless, in three more swings of his sword, her special items will be gone. Urahara asks Yoruichi if she can do it and she agrees she only needs to avoid using her left leg. However, Aizen appears next to her and attacks, causing a massive explosion in the area.

With Yoruichi's right arm-guard destroyed, Urahara asks if she is alright, and she rebuffs his concern. Aizen comments that Urahara's worrying act is part of his strategy. Urahara replies that he'd thought Aizen had stopped being cautious to which Aizen replies that he wasn't being so; he was merely making an observation. He goes on to explain that he has an interest in Urahara as he is the one person who has an intellect that surpasses his own. However, Urahara insists he's just a poor candy store owner now. He uses '''Hadō #32. Ōkasen''' which is blocked by Aizen who deduces he is planning a sneak attack. Yoruichi appears, but Aizen easily blocks her incoming attack with his left hand, however, she activates Shunkō which enables her to crack the right side of his body, causing him to fall into the town below. She moves to continue her assault, but Aizen catches her fist and reminds her he can't be defeated like this. Urahara ensnares Aizen using Shibari, Benihime, which fails to worry him. Urahara then uses Hiasobi, Benihime, Juzutsunagi, causing a huge explosion in Aizen's vicinity. As the blast clears, he is barely harmed by the attack and asks if this was really Urahara's trump card. When all of a sudden, Isshin appears in front of Aizen and hits him at point blank range with a Getsuga Tenshō.

Aizen is engulfed in an explosion that creates a large crater and destroys several buildings. They can't determine its effectiveness as they can't sense Aizen's Reiatsu since he transformed. Aizen emerges from the attack with a large slash on his face, agreeing that it was a palpable hit and that he "'understood'" the attack. He then raises his sword and says that it's time for them to understand his power.

Aftermath
Aizen easily defeats his opponents and goes to Gin and Ichigo's location. Aizen asks Gin what he was doing to Ichigo, and Gin claims that he was merely testing Ichigo's strength. Aizen turns away from Ichigo and orders Gin to open a Senkaimon to Soul Society, where the Real Karakura Town is, as it will be easier to storm the Royal Palace by creating the Ōken in Soul Society. Ichigo yells at Aizen to wait. Aizen turns, but his "face" seems to be falling off, to which Gin remarks that Aizen's incubation period must be over. Aizen fully turns and reveals his old face under the chrysalis, although he sports longer hair and black sclera, reminiscent of a Hollow. He then declares he can watch the fall of Soul Society with his own eyes. As Gin opens a gate, Aizen turns to Ichigo and says that they are leaving him there and that "eating" him can be done after all is finished, and disappears with Gin inside the gate. Ichigo stares as the gate closes, but is reprimanded by his father for just standing there. Isshin gets up and puts his arm around Ichigo, looking for support as he tells Ichigo to open a gate himself so that they can go and protect Karakura Town.