Return of the Zanpakutō Spirits

 is an event taking place in the Zanpakutō Rebellion. It focuses upon the Zanpakutō Spirits being freed from their brainwashing by Captain Mayuri Kurotsuchi, proceeding to assist their fellow Shinigami in the Human World in the fight against Muramasa.

Prelude
Captain Byakuya Kuchiki defeats Kōga Kuchiki, as Muramasa is enveloped in crimson Reiatsu. He calls out for his Shinigami master, as black Reiatsu is released from his body, forming into Hollows. Ichigo Kurosaki uses a Getsuga Tenshō to kill several Hollows, wondering why Muramasa kept Hollows within his body. Rukia postulates that it was to sustain his existence, but since he lost control of his Reiatsu, the Hollows began pouring out.

Rukia Kuchiki sympathizes with Muramasa's predicament, stating that he sacrificed everything for his master, and that he is only staying alive through willpower. Muramasa's Reiatsu starts to attract Hollows, to which Ichigo resolves himself to dispatch the Hollows. He fires another Getsuga Tenshō, which does minimal damage, as Uryū Ishida intervenes, killing the remainder of the Hollows with his Ginrei Kojaku. Ichigo comments that his Quincy Bow is similar to a can of bug spray.

Yasutora Sado and Orihime Inoue appear on the scene, as a Menos Grande fires a Cero at the congregating group. Orihime intervenes using Santen Kesshun to divert the attack, as Ichigo wonders what is going on with Muramasa. Suddenly, Muramasa's Reiatsu implodes, forming an inexorable vortex, drawing all of the Hollows into it. Ichigo and his friends run to the scene, as the Menos also get sucked into the vortex. The sphere surrounding Muramasa collapses, causing a large explosion in the middle of the lake.

The Hollow Within
The Reiatsu dissipates, as Muramasa's new form appears, similar to that of an Arrancar. Ichigo wonders whether that truly is Muramasa, to which Rukia explains that, since Shinigami and Zanpakutō are supposed to live in symbiosis with one another, and since Muramasa's master had been sealed, he required a new source of energy to maintain his existence, which is why he absorbed numerous Hollows. She states that this shows Muramasa's dedication to his master, as he releases purplish Reiatsu.

As Muramasa roars, Rukia states that his Reiatsu will consume all of Karakura Town if not stopped, as Ichigo and his friends proceed to go on the offensive. Muramasa charges at them, as Rukia comments upon his superior speed. He knocks Ichigo back, as Uryū fires a multitude of arrows from his Ginrei Kojaku, which Muramasa is able to dodge. He turns to face the Quincy, as Uryū fires off another barrage of arrows, which he is able to evade once more. Defenseless, Muramasa charges at Uryū, slamming him into the ground.

Muramasa speeds off into the distance, charging this time at Orihime and Rukia. However, Sado intervenes, using his right arm to stop the attack. He hurls Muramasa across the ground, who levels himself with his sword. Ichigo slams down upon Muramasa, who blocks with his arms. He is knocked back with an arm swing from Muramasa, raising his blade to him once more. Orihime notes that his eyes are very despondent, sympathizing with Muramasa's predicament.

However, Muramasa raises his right arm, charging up a blue Cero, sending it hurtling towards a surprised Orihime and Rukia. The attack is negated by Byakuya Kuchiki's Shikai, who appears before them. Rukia is glad that he is okay, as Ichigo asks him whether he was able to finish off Kōga. Byakuya asks him whether he had any doubts about his fighting ability, to which Ichigo states that he looks beat up. Rukia states that they should heal his injuries, but he dismisses this notion, stating that Muramasa should be dealt with first.

Byakuya observes that he must have undergone a full transformation, in order to be able to fire a Cero. Muramasa roars again, lightning crackling from the tension, as he tries to break free from the Hollow's control. Rukia wonders whether he will be able to resist the urges, as Orihime appears before him, telling him to stop fighting. Orihime states that his Shinigami master is dead, as Rukia explains that Muramasa is too far gone for her to be able to reason with him.

However, Orihime persists, stating that he is still partially in control, as Muramasa states that he cannot give in. He calls out Kōga's name, leading Rukia and the others to believe that he is still searching for him. Orihime continues, saying that he need not push himself any further, and that it will only cause his suffering to increase. Orihime walks closer to him, trying to prove a point, but Muramasa goes berserk, attacking her. She blocks with her Santen Kesshun, the force of the impact sending her hurtling backwards.

Rukia rescues her, as Muramasa prepares to deal the final blow. However, Ichigo blocks his attack, pushing Muramasa back, as Rukia asks whether she is alright. As Ichigo clashes with Muramasa, the fight seems evenly matched, as Orihime wonders whether saving him is still possible. Rukia and Orihime observe their battle, as Muramasa retreats to the air, firing off a multitude of Bala blasts, causing a cloud of dust to culminate.

However, Ichigo emerges unscathed due to his Hollow mask, as they proceed to clash in mid-air. As their blades cross multiple times, Muramasa releases a Cero, which Ichigo counters with his Getsuga Tenshō. He is able to destroy the Cero, his attack hitting Muramasa. Ichigo pants heavily, his Hollow mask dissipating, as Muramasa's body seems to be split in half. However, he uses High-Speed Regeneration, healing his injuries, exhuming black Reiatsu from his body.

Ichigo charges at Muramasa as he is attacked by a horde of Hollows trying to reach the Zanpakutō Spirit. Uryū and Sado notice the large numbers of Hollows forming, proceeding to split up and exterminate them. Uryū manifests his Quincy Bow, making easy work of the Hollows. Sado does the same, however, more Hollows emerge in their wake. Rukia uses Hadō #33 Sōkatsui, killing any Hollows which come near. Byakuya releases his Shikai, killing all nearby Hollows.

Ichigo is struggling to get any leeway between him and Muramasa as the Hollows swarm around him. He manages to defeat them, charging at Muramasa again, firing a Getsuga Tenshō at him. The attack runs Muramasa through, resulting in Muramasa falling to the ground. As Ichigo lands on the ground, Muramasa emerges with minor injuries, stating that he cannot lose. Muramasa's Reiatsu implodes once again, as his Reiatsu forms a huge dome, immersing Ichigo and himself within it.

The Zanpakutō Return
Orihime and Rukia notice that they cannot sense Ichigo's Reiatsu, as the dome continually expands, forming Menos in its wake. As Rukia and Orihime run from the enormous Menos, Uryū notices that the Garganta in the sky is gradually getting bigger. The Menos fire countless Cero from their mouths, but Byakuya is able to evade them all, cutting them down with his Shikai. As Rukia and Orihime run from the pursuing Menos in their wake, it fires a Cero at them, which is destroyed by one of Sode no Shirayuki's attacks.

She apologizes for her lateness, stating that she isn't the only one who has arrived. 3rd Seat Ikkaku Madarame announces that the main cavalry has arrived, as the other Shinigami and Zanpakutō Spirits appear before their eyes. Lieutenant Renji Abarai apologizes also, as Sado realizes that not all of them are Shinigami, to which Orihime wonders whether their Zanpakutō Spirits are also with them. Uryū wonders what is occurring, as he thought the Zanpakutō Spirits were rebelling, but Sode no Shirayuki states that Captain Kurotsuchi was able to undo the brainwashing Muramasa subjected them to.

Haineko explains that that is what occurred, as Tobiume apologizes for the trouble they caused. She states that now is the time for the Zanpakutō to prove their worth to the Shinigami.

Shinigami and Zanpakutō: United
The Zanpakutō move out, proceeding to kill all of the Menos in their wake. As Hōzukimaru cuts apart a Menos, Ikkaku berates him, asking whether he is trying to outdo him. Hōzukimaru asks what his problem is, stating that they are fair game, as the Shinigami-Zanpakutō relationship doesn't apply in this situation. 5th Seat Yumichika Ayasegawa shakes his head, stating that they are unaware of how ugly rushing about can be. Ruri'iro Kujaku counters, stating that it is even uglier to act jealous.

The Menos move out in an attempt to attack their new opponents. Uryū notices that the Menos are coming in their direction, prompting Sode no Shirayuki to use Some no mai, Tsukishiro, freezing the creature, shortly before it shatters into nothingness. Another Menos charges up a Cero at the group, who prepare to counter, but Captain Suì-Fēng intervenes, slashing the Menos in one quick movement. The Cero is released into the sky, as the Menos evaporates. Suì-Fēng appears, stating that they can't let the Zanpakutō have all the fun.

Sado thanks her for saving them, but she states that it wasn't her intention, and that she was just doing what needed to be done. She moves off, heading in the direction of the dome, but is stopped by Uryū's arrows. Rukia asks what he is doing, to which he states that she could destroy the town whilst attacking it. Suì-Fēng states that she doesn't care, and that it is her sole duty to destroy the dome. However, Captain Tōshirō Hitsugaya intervenes, stating that they need to focus on killing the Hollows first.

This seems to satisfy Suì-Fēng, who uses Shunpo to move away. Hitsugaya tells Rukia that, if she wants to find out what is happening to Ichigo in there, then she ought to search for his Reiatsu. As they look up at the Hollow Dome, Hitsugaya moves out, attacking a Menos with relative ease. He notices that there are a large number of enemies, and that, even with their Zanpakutō on their side, they cannot possibly deal with all of them. Suì-Fēng states that Captain Kurotsuchi is still working on the other Zanpakutō, and that they cannot afford to wait for them.

Hitsugaya states that it is up to them to kill all of the Menos, a task which Suì-Fēng accepts. Byakuya faces off against a group of Menos, whereupon Senbonzakura appears by his side, stating that he will watch his back. As the Zanpakutō cut down all of the Menos in their path, they notice Byakuya's presence, stating that he tricked them good. Renji cuts down the Menos in Byakuya's path, asking whether his captain is alright. Zabimaru appears beside Renji, who states that he is going all out, since Karakura Town has been locked.

Chimpette states that she isn't going to help him if he is unable to control his powers, as Renji tells them to not say another word. He tries to tell him what the others are all thinking, but Byakuya moves out before he can say it, as both Chimpette and Snakey laugh at him for trying to act cool. Lieutenant Izuru Kira tells Lieutenant Marechiyo Ōmaeda that they are heading out, to which Ōmaeda states that he will show everyone that they are no match for him. He attempts to release his Zanpakutō, but is kicked in the back by Gegetsuburi.

He recovers, asking Gegetsuburi what his deal is, wondering whether he is still under Muramasa's control. However, Gegetsuburi states that that isn't what this is about, telling him to address him with an honorific. He refuses to, as Kira watches on in shock. During their argument, the Menos proceed to surround them, as Ōmaeda and Gegetsuburi come up with all sorts of different excuses as to why they approached them. Kira ignores them, releasing his Zanpakutō, as Captain Sajin Komamura proceeds to destroy the Menos.

As Komamura does so, he states that he has been taking things too easily, saying that if they do not hurry, he will defeat all the enemies before them. Rukia states that she cannot sense Ichigo's Reiatsu at all, to which Uryū states that it is pointless to be doing nothing. He fires several arrows at the dome, all of which are absorbed into the massive structure. He wonders just what the dome is, as Rukia states that even a captain utilizing Bankai would experience difficulty in destroying it.

While they are talking, the Garganta continues its expansion, releasing a black sludge. As the sludge makes contact with the ground, numerous Menos Grande form from it, much to the surprise of both the Shinigami and the Zanpakutō Spirits. The Hollow dome releases extreme Reiatsu, growing larger while it does so, as Rukia states that it is causing the Garganta to expand and draw forth the Menos. She states that, if left unattended, a near infinite number of Menos will emerge from the tear.

As the tear expands, the Menos prepare to materialize in the Human World, as Byakuya and Senbonzakura attempt to seal the rapidly expanding crevasse. They pool their attacks into the Garganta, preventing the Menos from surfacing, as the other Shinigami watch on. The Shinigami and the Zanpakutō Spirits then go on the offensive, killing large numbers of Menos in their path. They then release their maximum amount of Reiatsu, combining to force the Menos back into Hueco Mundo.

The combined effort forces the Garganta to close, as the Shinigami and the Zanpakutō Spirits emerge victorious. Captain Suì-Fēng wonders whether they completely sealed off the Garganta, to which Captain Hitsugaya confirms that they have. Senbonzakura asks Byakuya whether he is alright, to which he asks Senbonzakura who he is talking to. The Zanpakutō Spirits comment that, although he seemed to be doing fine, in the end, he still needed their assistance.

Aftermath
They move out to face off against the remaining Hollows, as Uryū notices, despite all their efforts, the Dome is still increasing in size. Orihime asks whether they will be able to save Ichigo, to which Rukia states that it is entirely up to Ichigo to stop the expansion of the Dome.