Ichigo Kurosaki & Hollow Ichigo vs. Zangetsu & Muramasa

Ichigo Kurosaki & Hollow Ichigo vs. Zangetsu & Muramasa is a battle in the Zanpakutō Rebellion wherein Muramasa released the spirit of Zangetsu in order to fight Ichigo. Having lost access to his Shinigami abilities, Ichigo draws on his Hollow powers to fight.

Prologue
After Rukia finishes her fight with Sode no Shirayuki, Ichigo is confronted by Muramasa who reveals himself to be a Zanpakutō spirit. When Muramasa reveals that he knows Ichigo's name, Ichigo asks how he knows this. Muramasa says that it is not important but that his goal is to free all Zanpakutō spirits from Shinigami control. Ichigo becomes angered by this and yells at Muramasa, asking how to return Rukia's Zanpakutō back to normal. Muramasa instead asks his own question, what are Zanpakutō? Ichigo is confused by this and Muramasa states that a Zanpakutō is a soul born within their Shinigami's heart and they share the same Reiatsu as their Shinigami, therefore they are always within their Shinigami. Muramasa then explains the development of Zanpakutō's, detailing the process through which Shikai and Bankai are achieved. Muramasa then says that a Zanpakutō does not have to live in symbiosis with their Shinigami. Ichigo asks what this means and Muramasa reveals that Zanpakutō's have wills of their own. Ichigo is shocked to hear this. Muramasa then says that Zanpakutō's have their own souls that are just as important as a Shinigami's. When Ichigo expresses disbelief, Muramasa says that that is what makes Shinigami so arrogant. Ichigo tries to counter this but Muramasa continues, saying that he understands Zanpakutō's and can reach out to their souls. Those who commiserate with his plan take own their true form. Ichigo calls this impossible but Muramasa says that any Zanpakutō that answers his call becomes an entity separate from their Shinigami.

Ichigo angrily asks why Zanpakutō listen to him and Muramasa says that it is their desire, stemming from the Shinigami's oppression. Rukia then manages to get out a few words, saying she has never looked down on Sode no Shirayuki. Muramasa says that she is alone in that opinion as Sode no Shirayuki answered his summons. As Rukia begins to lose strength again, Muramasa tells her that her part is done, making Rukia question him. Muramasa explains that he will free every Zanpakutō from their Shinigami, no exceptions. In order to do so, he helped Rukia get to the Human World to bring Ichigo back. Ichigo says that Muramasa will not get away with this and says they should change locations. Muramasa agrees and they head off. Ichigo attacks Muramasa who summons his sword and defends. Muramasa unleashes an attack and Ichigo counters with a Getsuga Tenshō, which Muramasa easily evades. As he searches for the Zanpakutō spirit, Ichigo begins to see the world warp around him. Muramasa then calls out to Ichigo, telling him to sheathe his sword. Ichigo tries to attack different areas to find Muramasa but the world around him soon begins to spin. After falling down, he is pulled forward and pinned to the ground. Muramasa then reappears and kicks Ichigo's sword away. He sticks his hand out and begins to recite a chant. As he does so, Ichigo spins in place and a dark energy appears around him. When he finishes the chant, Muramasa reaches into Ichigo's chest and pulls out a chain as smoke fills the area. When the smoke clears, the manifested spirit of Zangetsu appears next to Muramasa before attacking Ichigo.

Battle
Zangetsu pushes Ichigo back and Ichigo asks Zangetsu what is going on. He asks if they were not of one body and soul but Zangetsu does not answer. Zangetsu then appears behind Ichigo and knocks him into the wall before firing a Getsuga Tenshō at him. Muramasa walks over and is surprised to see that Ichigo could still move but says that it does not matter as the fight is already over. Ichigo manages to get to his knees and asks Zangetsu if he is really serious about this. Zangetsu responds by firing another Getsuga at Ichigo. As the smoke clears from Zangetsu's attack, Ichigo stands before Zangetsu and Muramasa with half of his mask on and grinning. He opens his eyes, revealing that Hollow Ichigo has taken over. He lunges at Zangetsu and perpetually knocks him back with a series of hits. Zangetsu recovers and prepares to counter but Hollow Ichigo evades and grabs Zangetsu by the face and throws him back into a wall. Muramasa then asks who he is and Zangetsu says that that is another soul that resides in Ichigo. Zangetsu fires another Getsuga but Hollow Ichigo counters with his own. Hollow Ichigo goes to attack again and Zangetsu evades multiple time, moving the fight elsewhere. As Hollow Ichigo's attacks continue, Zangetsu effortlessly dodges before countering and cutting his opponent across the chest. However, the wound quickly regenerates and Zangetsu attacks again, cutting Hollow Ichigo across the shoulder sending Hollow Ichigo to the ground squirming. However, a large creature appears from the wound and attacks Zangetsu. Zangetsu dodges initially but is swallowed in the second attack. Zangetsu manages to break out but Hollow Ichigo emerges, now having taken over more of Ichigo's body. A swirling black Reiatsu surrounds Hollow Ichigo which then envelops him and explodes. When all settles, Hollow Ichigo has now completely taken over Ichigo's body as lines of black reiatsu emanate from his back. Muramasa is startled by this output of reiatsu. Hollow Ichigo jumps high into the air before crashing down on Zangetsu and going into a berserk rage. Zangetsu manages to block most attacks but one slips through and cuts his arm. Hollow Ichigo then headbutts Zangetsu, knocking him back and fires a large cero from the palm of his hand. Zangetsu quickly counters with a Getsuga but it does little to stop the monstrous cero. Zangetsu is knocked far back and as Hollow Ichigo looks on, Muramasa strikes him from behind, but the wound closes up instantly. Hollow Ichigo then turns around and knocks Muramasa away. Hollow Ichigo slowly approaches Muramasa but falls down as his mask begins to crack. Ichigo calls out that he will not let Hollow Ichigo have his body and tears the mask off of his face. Blue and Black reiatsu envelops Ichigo before shooting out and destroying a large portion of the area. As the dust settles, Hollow Ichigo's body is completely cracked. It then breaks apart, leaving Ichigo in his original form. A weakened Ichigo then calls out for Zangetsu several times before collapsing.

Ichigo awakens in his inner world and begins remembering about his fight with Zangetsu. He calls out to Zangetsu, questioning if he really left his body. Muramasa then appears and confirms this for Ichigo. Ichigo asks how Muramasa got in there but Muramasa says that it was easy with his special abilities. Ichigo questions Muramasa as to what he is trying to accomplish and asks what his wielder thinks. Muramasa then says that he killed his wielder. Ichigo is taken a back by this. Muramasa then says that he is interest in Ichigo and asks about his Hollow powers. Ichigo refuses to say anything but Muramasa says that Ichigo's power is useless before him. Ichigo pulls out his sword and attacks but Muramasa merely sticks out his hand and knocks Ichigo out. Ichigo hears a voice calling to him that he believes is Zangetsu and begins to awaken. However, as he looks Muramasa is the one standing before him. Ichigo stands up to see himself upside down and the colors around him distorted. Muramasa calls to him and Ichigo soon finds himself unable to move. A hole opens in his chest and many white hands begin to slither out and entangle him. The world then flips and changes to normal colors, revealing Muramasa to be using his abilities on Ichigo. A white mass begins to pour out of Ichigo and slip into Ichigo's actual inner world. The mass turns black and begins to grow before forming into a black cloth. The cloth then rips apart, revealing Hollow Ichigo. Muramasa is fascinated by Hollow Ichigo's existence. Muramasa asks who Hollow Ichigo is exactly and Hollow Ichigo responds that he is Ichigo's true form, his instincts if he will. Muramasa realizes that Hollow Ichigo had control during Ichigo's fight with Zangetsu. Hollow Ichigo then asks Muramasa who he is. Muramasa says that he is a Zanpakutō and that Zanpakutō answer his call and that he then awakens their inner instincts. He says that he will awaken Hollow Ichigo's inner instincts and uses his abilities to seemingly freeze Hollow Ichigo in place. As he approaches though, Hollow Ichigo attacks.

Hollow Ichigo and Muramasa have a short stand off before Hollow Ichigo goes into a berserk rage, slashing at Muramasa repeatedly. Muramasa however has little trouble in dodging and tells Hollow Ichigo to show him his real power. Hollow Ichigo then charges at Muramasa and attacks with great speed, which Muramasa makes note of. Hollow Ichigo then begins to use his sword like a flail and gets behind Muramasa before throwing it, sending Muramasa flying. Muramasa then asks if Hollow Ichigo is a Hollow and was in control of Ichigo on the outside but the only answer he gets is a maybe. Muramasa says that it does not matter anyway and says that he has learned that a Shinigami has another force they must suppress, Hollow Ichigo accuses Muramasa of mocking him, saying Ichigo does not suppress him. Hollow Ichigo thens ays that whatever Muramasa is planning, it will not work and that he will devour Ichigo and take over his body for good. Hollow Ichigo and Muramasa then break into combat once more. Hollow Ichigo puts Muramasa on the defensive before taunting him. Muramasa responds by backing off and using a technique. Hollow Ichigo tries to escape but is soon halted in the air and slammed to the ground by an unseen force. As he tries to get up, he finds he cannot move. Ichigo then looks up and sees the reflection of Muramasa and Hollow Ichigo above and is able to see the many invisible threads that hold Hollow Ichigo captive. As Muramasa goes to finish Hollow Ichigo, Ichigo gets up and uses a Getsuga Tenshō to free Hollow Ichigo. Muramasa is surprised to see Ichigo recovered so quickly and Hollow Ichigo questions why Ichigo saved him. Ichigo says that he does not know what Hollow Ichigo will do but they have a job to do. When Muramasa asks if Ichigo was protecting his Hollow powers, Ichigo says that Hollow Ichigo is a part of him and that Muramasa is an outsider and tells him to get out. Muramasa says that he cannot fathom a relationship between a Shinigami and a Hollow but Ichigo responds that he is Human and charges at Muramasa. Ichigo then forces Muramasa out through sheer willpower. Ichigo opens his eyes back in Soul Society and tells Muramasa that he will get Zangetsu back and that he will not lose.

Muramasa says that he would not have expected a Shinigami to intrigue him as much as Ichigo has but Ichigo tells him to cut the chatter and charges at him, only to have his attack blocked by Zangetsu. Ichigo tells his Zanpakutō that he will fight to get him back and asks Zangetsu what he has to say. Zangetsu says that he wishes to know which of them is stronger and will raise his blade to find that out. Ichigo watches as Zangetsu prepares to attack before Hollow Ichigo calls to him, saying that since he can't use his powers as normal, he will lend Ichigo a hand but he will not be able to use his mask. Ichigo grabs his blade with both hands and prepares to attack but Zangetsu activates Bankai. Zangetsu fires a powerful Getsuga that knocks Ichigo far back. Out of breath, Ichigo questions if he has always had that kind of power. He gets up and tries to activate his Bankai but it fails. Zangetsu says that Ichigo cannot activate Bankai as long as he refuses to lend him his powers. Zangetsu fires another Getsuga and Ichigo dodges. As he fires another, Ichigo attempts to use his mask but remembers that he cannot currently. Ichigo then fires his own Getsuga, stopping the other. Ichigo questions why Zangetsu wants to find out who is stronger and the Zanpakutō responds that he has given all he could to Ichigo to make him stronger and he no longer has anything to teach him and that should Ichigo die by his blade, so be it as it is entirely up to Ichigo if he can surpass him. Ichigo resolves to prove just how strong he is then. Ichigo looks at his blade and Hollow Ichigo says that using him will not be easy. Ichigo says that he knows but tells him to get ready. As their battle resumes, Zangetsu attacks from above but Ichigo dodges. Zangetsu then gets behind Ichigo and knocks him to the ground before berating him for not using his full strength. Ichigo gets up and, drawing on Hollow Ichigo's power, he tells Zangetsu he has learned to use him before going on the offensive, pushing Zangetsu back. Zangetsu says they will get nowhere stalling the fight and says they should end it. Both opponent's fire a Getsuga at each other, with Ichigo's taking on a new, Hollow like shape. The two attacks meet in stalemate before Hollow Ichigo decides to give Ichigo more of his power to prevent Ichigo from dying. The sudden surge in power amazes Zangetsu who is then swallowed by Ichigo's attack which consumes a large area and is seen across Seireitei.

Aftermath
Zangetsu reverts to his sword form and Ichigo tells Muramasa that he is next. Surprised, Muramasa asks Ichigo if he had any hesitations in attacking his Zanpakutō. Ichigo replies no and Muramasa is shocked. Ichigo explains that Zangetsu is a part of him and he knew Zangetsu would accept him and his power. Muramasa says that he sees but suddenly becomes ill. He repeats what Ichigo said and says it is interesting but begins to grow sicker and his body begins to fade. He then disappears in a flash of green light. Suddenly, Zangetsu returns to his spirit form and Ichigo asks if he is okay. Zangetsu says he is alright now since he is free of Muramasa's mind control. Zangetsu explains that Muramasa awakens a Zanpakutō's instincts and uses it to control them. Ichigo asks if he is controlling all the Zanpakutō and Zangetsu says that it is likely so. Zangetsu tells Ichigo that he truly saved him and Ichigo says that Hollow Ichigo helped. Zangetsu then questions what Ichigo will do, to which he responds that he will go after Muramasa.