The Armies Assemble: Battle at Fake Karakura Town

The Armies Assemble: Battle at Fake Karakura Town is the preceding event before the many battles to occur at Karakura Town. It is the confrontation between the Gotei 13 and Sōsuke Aizen as each respective side's are gathered up and assembled to do battle.

Prelude
After the fight against Nnoitra Gilga is finished, Orihime Inoue heads off to heal Captain Kenpachi Zaraki. Before Orihime reaches him, she is whisked away back to Aizen by Coyote Starrk. After "thanking" Orihime for her "services", Aizen makes an announcement to all of Hueco Mundo, stating that Orihime is in the fifth tower, should anyone want to retrieve her as she is now of no use to him, and that he has closed the Garganta that the Captains used for entry into Hueco Mundo. He informs them that he is leaving to destroy Karakura Town and that he will deal with all the intruders once he has finished up. Ichigo is about rush away, but Kenpachi tells to wait as Captain-Commander Genryūsai Shigekuni Yamamoto was anticipating an attack from the Arrancar and planned on defending Karakura Town with the rest of the Gotei 13 from the start.

Arrival and Confrontation, Swang The Edge Down
Not only had Yamamoto planned on defending Karakura Town from the start, they had taken the precaution to make it safe for the Gotei 13 to fight with their full power by having Kisuke Urahara and the Shinigami Research and Development Institute use Tenkai Kecchu to replace Karakura Town with an abandoned facsimile. As Aizen enters the Human world, he is "greeted" by the remainder of the Gotei 13. Yamamoto remarks that it seems they made it in time. Aizen then questions on how Yamamoto is able to say such a thing as he is aware that the Karakura Town below is fake and it is no threat to him. He then summons his top three Espada who come with their Fracción: Coyote Starrk, Baraggan Louisenbairn, and Tier Harribel to fight the Gotei 13. Aizen only muses that if Karakura Town is in Soul Society then he will just go to Soul Society to destroy the real town and simply decimate the Gotei 13 at the fake Karakura. He also informs Ulquiorra Cifer to take charge of Las Noches.

As Aizen and his subordinates come together, their combined reiatsu is so powerful that a group of Hollows 22 kilometers away are fearfully shaking and explode because of this heavy spirit pressure. Lieutenant Marechiyo Ōmaeda fearfully remarks on the monstrous size of their reiatsu to which his captain tells him that he can run if he wants. Lieutenant Tetsuzaemon Iba asks if they ought to directly attack Aizen first, but Captain Sajin Komamura tells him that it is best that they defeat the others first so they can concentrate on Aizen because of Aizen's unique abilities. Captain Shunsui Kyōraku wonders on who is the strongest of the three Espada to which Captain Jūshirō Ukitake remarks that it is hard to say as they would need to ask Aizen. Captain Tōshirō Hitsugaya then comments that their problem is not knowing if Aizen will interfere while they fight the Espada. Seeing this, Yamamoto tells the rest of the Gotei 13 to step back as he releases his Shikai. The reiatsu is incredibly immense as Yamamoto uses Jōkaku Enjō to entrap Aizen, Kaname Tōsen, and Gin Ichimaru in a blazing sphere of flames. With this, Yamamoto tells the Gotei 13 to go and finish the Arrancar as Aizen will not be able to escape for some time. Inside the prison, Gin asks on what to do since now they could not join in. Aizen simply remarks that there is no need for them get involved as the battle will end without them lifting a finger (because the power of the Espada alone will suffice to defeat the Gotei 13).

Five Towers/Four Pillars
With Aizen, Ichimaru, and Tōsen incapacitated by Yamamoto's Jōkaku Enjō, Baraggan Louisenbairn assesses the situation, noting that their enemies are numerous and their leader (temporarily) removed from the battlefield. Tier Harribel tells him that he is underestimating Aizen to which Baraggan states he thinks she is underestimating him. He snaps his fingers and his Fracción pull out a throne of bones for him to sit on as he analyzes the situation. He then decides to takes control of giving all orders and openly threatens the other Espada for the leadership, telling Starrk he'd "better not have a problem with that." His comrade, Starrk, lazily agrees, which earns him a kick from his Fracción, Lilynette Gingerbuck. Harribel and her Fracción could not care less. Baraggan then speaks to Yamamoto, noting that the "jūreichi" beneath them is a fake that was replaced by a replica created in Soul Society. He then repeats Aizen's statement of simply going into Soul Society to destroy Karakura Town and questions if they have to go through all that trouble. He then goes on to say that according to Aizen's explanation, there are four pillars set up at each corner of the city that are keeping the real Karakura Town in the Soul Society. He then wonders what will happen if the pillars are destroyed and calls for Findorr Calius to take action. Findorr calls for four gigantic Hollows that appear at each pillar as Baraggan confidently states that they know where the pillars are, aware that destroying the pillars will swap the real Karakura Town back. Ōmaeda then begins panicking that their enemy know the pillars' locations and that the real Karakura Town will become a battlefield. This prompts Yamamoto to simply call Ōmaeda and the Espada fools as all four Hollows are quickly killed off. Baraggan, Harribel, Starrk and Ōmaeda notice this. Yamamoto reprimands them for thinking that they would leave such important locations unprotected as there are strong warriors stationed at each pillar. Those four fighters are revealed to be Lieutenant Izuru Kira, Yumichika Ayasegawa, Ikkaku Madarame, and Lieutenant Shūhei Hisagi.

Ants and Dragons, Setup for the next round
Ōmaeda is in complete shock over the presence of the four officers as he thought that they were to hold things up at Soul Society. This prompts him to ask if the rest of the Gotei 13 knew to which Shunsui Kyōraku, Lieutenant Rangiku Matsumoto, and Suì-Fēng confirm. Baraggan, however, is unimpressed. He states if the Gotei 13 have four "ants" to protect the pillars, he will send four "dragons" in response. He sends four members of his six Fracción (Choe Neng Poww, Findorr Calius, Charlotte Chuhlhourne, and Abirama Redder) to kill them. Charlotte, Abirama, Findorr and Poww are sent to battle Yumichika, Izuru, Shūhei, and Ikkaku, respectively.

Aftermath
The Gotei 13 replace the real Karakura Town with a replica as they prepare to battle Aizen. Both the Gotei 13 and Aizen gather their forces to fight at the fake Karakura Town. As the Gotei 13 confront Aizen and his invaders, Captain-Commander Yamamoto traps Aizen, Gin and Tōsen in a cage of fire. The four critical pillars that keep the fake Karakura Town in place are revealed to have four guardians: Izuru Kira, Yumichika Ayasegawa, Ikkaku Madarame, and Shūhei Hisagi. These four guardians will then fight four of Baraggan Louisenbairn's Fracción: Choe Neng Poww, Findorr Calius, Charlotte Chuhlhourne, and Abirama Redder. The rest of the Gotei 13 and the other Arrancar part of Aizen's invasion force would watch on as these fights commence.