When Sōsuke Aizen leaves Hueco Mundo for the Human World, he leaves control of Las Noches to Ulquiorra, who returns from the alternate dimension Grimmjow Jaegerjaquez sealed him in by ripping an opening into one of the towers. Upon returning, Ulquiorra finds Orihime Inoue in the same tower and stares at her. Elsewhere, Ichigo, who is in his Bankai, senses Ulquiorra's arrival and tells Kenpachi Zaraki that his duty is to protect his friends before rushing toward the tower to confront Ulquiorra.
Walking toward Orihime, Ulquiorra asks her if she is scared and states Aizen has discarded her before noting there is nothing left to protect her. Ulquiorra goes on to state she is going to die here without anyone else around before noting he has been told this should be frightening, only for Orihime to firmly state she is not afraid because her heart is with everyone who came to rescue her.
As Ichigo kills two Hollows on his way to the tower, Ulquiorra states he finds this ridiculous and asks Orihime if she really means this, prompting Orihime to confirm this and explain how she initially could not understand why they had come to save her before she realized that she would be doing the same thing if any one of them had disappeared like she had.
Meanwhile, Ichigo arrives at the base of the tower and leaps upward, only to be confronted by Rudbornn Chelute and his Exequias. When Rudbornn attacks him and introduces himself, Ichigo knocks him back and proclaims he does not have time to deal with them before attempting to fire a Getsuga Tenshō. However, he is swarmed by the Exequias, prompting him to wonder how many of them there are.
Ichigo is saved when Zabimaru smashes into several of the Exequias, sending them flying away. On the ground below, Renji Abarai attacks the rest of the Exequias around Ichigo, who calls out to him. Yasutora Sado uses El Directo on the pillar which Rudbornn and the Exequias are standing on, causing it to break apart and crumble beneath their feet. Telling his soldiers to not be distracted by this, Rudbornn leaps toward Ichigo.
However, Rukia Kuchiki stops him by using Tsugi no mai, Hakuren, which encases his right arm in a horizontal pillar of ice. When Ichigo calls out to her, Rukia tells him to save the conversation for later and get going, which Ichigo agrees to. In the tower, Orihime admits to Ulquiorra that it may be impossible to feel the same way as someone else before telling him people can unify their hearts by caring about each other and putting their hearts close together.
Ulquiorra notes that she mentioned hearts and says humans always speak of such things like they carry their hearts in the palms of their hands before stating his eye perceives all without overlooking anything. Ulquiorra goes on to explain how he has always fought under the assumption that what his eye cannot see does not exist before asking Orihime what the heart she speaks of is. As Ulquiorra asks Orihime if he will find it in her chest by tearing it open or in her skull by smashing it open, he is interrupted and startled by Ichigo, who crashes into the tower through the floor behind him.
Standing before Ulquiorra, Ichigo tells him to get away from Orihime, prompting Ulquiorra to remind him that his orders do not include killing Orihime. Ulquiorra goes on to explain how Ichigo is a different matter, as killing him is the same as protecting Las Noches, before drawing his Zanpakutō. Slightly surprised by this, Ichigo states he was not expecting Ulquiorra to draw his sword immediately and admits his first goal was to get Ulquiorra to do this. When Ichigo asks Ulquiorra if this means he has accepted him as a real opponent, Ulquiorra states he merely views Ichigo as someone who must be destroyed, prompting Ichigo to say this is enough for him.
Ulquiorra stabs at Ichigo, who dodges, causing Ulquiorra's sword to hit a pillar, which is heavily damaged. When Ichigo slashes at him, Ulquiorra blocks with his Zanpakutō before slashing at Ichigo, who ducks and attacks Ulquiorra. As Ulquiorra ducks, the pillar behind him is nearly cut in two by Ichigo's attack as Ulquiorra stabs at him with his sword. When Ichigo dodges, Ulquiorra stabs at him several more times in rapid succession, only for Ichigo dodge every attack while noting he can see Ulquiorra and react because Ulquiorra's fighting style has not changed from when he was only using his hands.
Telling himself that the hand which Ulquiorra was using merely has a longer reach, Ichigo watches closely and grabs Ulquiorra by the wrist, surprising him, before slashing him across the chest. Ulquiorra is sent skidding back several feet from the force of the attack, but reveals he has only suffered a minor cut next to his Espada tattoo. Noting that Ulquiorra's Hierro must be very strong for him to receive such a minor injury, Ichigo states he is much better at reading Ulquiorra's movements when compared to his performance during their previous battle, prompting Ulquiorra to ask him what he means.
Ichigo admits that he was completely unable to read Ulquiorra's movements, which made it feel like he was fighting against a machine or statue, before noting that being able to do so now means he has become more like a Hollow or Ulquiorra has become a little more like a human. Surprised by this, Ulquiorra splits the ground in front of him in two with a single strike from his sword and states that being able to fight at this level has gone to Ichigo's head. When Ulquiorra appears in front of him and attacks, Ichigo narrowly dodges and leaps back, only for Ulquiorra to appear behind him and attack once more. However, Ichigo is protected by Orihime's Santen Kesshun.
As Santen Kesshun shatters, Ulquiorra asks Orihime what she is doing, prompting her to express confusion. Asking Orihime if she did so because Ichigo is her friend, Ulquiorra wonders what made her hesitate the first time he attacked Ichigo. When Orihime fails to respond, Ichigo tells Ulquiorra to shut up before stating no one cares about why he believes Orihime hesitated. Thanking Orihime for helping him, Ichigo tells her to stay back so she does not get hurt before telling Ulquiorra he is surprisingly talkative. When Ichigo uses a Getsuga Tenshō, Ulquiorra states it will not work against him, only to be surprised when Ichigo rushes forward without firing it.
Ichigo clashes with Ulquiorra, creating a wave of energy upon striking Ulquiorra's sword, as Ulquiorra notes that Ichigo is creating attacks with the power of a Getsuga Tenshō behind them by keeping a Getsuga Tenshō in his sword without firing it. Repelling Ichigo, Ulquiorra notes Ichigo probably thinks he is clever for creating this attack before reminding him of how his Getsuga Tenshō did not work on Ulquiorra even when he was wearing his Hollow mask. As Ulquiorra states a Getsuga Tenshō from an unmasked Ichigo is useless no matter how he uses it, Ichigo attacks him once more with his Getsuga Tenshō-infused Tensa Zangetsu.
When Loly Aivirrne and Menoly Mallia accost Orihime and begin tearing her clothes off, Ichigo calls out to Orihime and rushes toward her while wondering who Loly and Menoly are. As Loly threatens to gouge one of Orihime's eyes out if he comes any closer, Ichigo prepares to fire a Getsuga Tenshō at her, only for Ulquiorra to intercept his attack, surprising Ichigo. Ulquiorra tells Loly he did not do this to save her as Ichigo attacks him once more before telling Ulquiorra to get out of the way. As Ulquiorra tells Ichigo he can fight someone else once he kills Ulquiorra, they are interrupted by the arrival of Yammy Llargo.
When Yammy says he has come to give him a hand, Ulquiorra asks Yammy when he asked him to interfere as Ichigo recognizes Yammy from the first invasion of Karakura Town. Yammy and Ulquiorra converse for a short period of time before Ulquiorra tells Yammy to either go back to sleep or deal with the captains below. When Yammy begins attacking Loly and Menoly, Ichigo attempts to help Orihime, only for Ulquiorra to intercept him once more and repeat his statement of Ichigo having to kill him before moving on to other opponents.
Yammy defeats Loly and prepares to attack Orihime, prompting Ichigo to call out to her. However, Uryū appears in a hole in the wall and shoots Yammy in the shoulder with a Heilig Pfeil, knocking him over in the process, before landing inside the tower as Ichigo calls out to him. When an enraged Yammy demands to know who Uryū is and where he came from, Uryū expresses surprise at Yammy not being pierced by a Heilig Pfeil shot with that much force. Yammy steps toward Uryū, who tells him to watch where he steps. As a large explosion engulfs Yammy, Uryū reveals that he placed an anti-Arrancar landmine created by Mayuri Kurotsuchi there.
As Ichigo expresses surprise, a moderately burnt Yammy grabs onto the edge of the hole in the floor and curses Uryū, who notes he could hear Yammy from the floors below before asking Yammy if he is the one Szayelaporro Granz was talking about. When Yammy confirms this, Uryū fires a Heilig Pfeil at the section of the floor which Yammy is hanging on to, destroying it, while admitting he feels a little sorry for Yammy because he could have enjoyed himself a little longer had Uryū not shown up. Yammy falls into the hole while cursing Uryū, who reveals Yammy should fall all the way down because he broke a few of the pillars on the way up.
When Ichigo says his name, Uryū calls him blithe for having questions in the middle of battle and explains how Mayuri healed him after Renji, which is why he was late, and gave him the mines, which explode when their Reiatsu sensors detect an Arrancar and which he planted through the ceiling of the floor below. Uryū asks Ichigo if he has any more questions, only for Ichigo to smile and reveal he did not have any questions to begin with before stating Uryū can be annoying when he begins babbling on his own. Turning away, Ichigo states he is entrusting Orihime's safety to Uryū.
Ichigo tells Uryū to protect Orihime with his body if her Santen Kesshun is unable to block his Reiatsu, only for Uryū to state he was going to do this even if Ichigo did not ask him. Turning to Ulquiorra, Ichigo apologizes for making him wait and states this is the Hollowfication which he wanted to see before donning his Hollow mask. Surprised by the increase in Ichigo's Reiatsu, Ulquiorra blocks Ichigo's subsequent attack and is shocked to see Tensa Zangetsu cut into his own Zanpakutō. Ulquiorra leaps through the hole in the wall to avoid a Getsuga Tenshō as Ichigo follows him.
Turning to face Ichigo in midair, Ulquiorra charges and fires a Cero at him, only to be shocked upon seeing Ichigo has completely blocked the blast with only his sword. When Ulquiorra begins rapidly moving up the side of the tower, a startled Ichigo tells him to wait and begins to follow him while wondering how far Ulquiorra is planning to go. Eventually, Ulquiorra blasts through the dome of Las Noches. As Ichigo emerges above the dome and realizes where they are, Ulquiorra confirms his observation and reveals Espada ranked 4 and above are forbidden from releasing their Zanpakutō within Las Noches before releasing his Zanpakutō, Murciélago.
A large amount of black-green Reiatsu explodes outward and falls around Ichigo in the form of rain. Ichigo's eyes widen in shock as he sees Ulquiorra's Resurrección, Murciélago. When Ulquiorra tells him to not lose his composure, Ichigo instinctively assumes a battle stance as Ulquiorra goes on to tell him to keep his fighting senses at their peak. Generating a Luz de la Luna in his hand, Ulquiorra appears in front of Ichigo and attacks him, resulting in a powerful explosion. Afterward, as Ichigo stands with part of his mask gone, Ulquiorra notes he instinctively released a Getsuga Tenshō and states he would have died had he not done so.
As the broken portion of Ichigo's mask hurtles away, Ichigo expresses disbelief at Ulquiorra's new level of speed and notes he could not react at all even with his mask on. Standing before Ichigo, Ulquiorra notes that the power of his Hollow mask has increased considerably alongside the time which he can wear it and notes it is pitiful that it can still be destroyed so easily before throwing a Luz de la Luna at Ichigo, who is cut on his right shoulder and sent flying back. Digging his sword into the ground to slow himself down, Ichigo reforms the broken portion of his Hollow mask.
Ulquiorra flies toward Ichigo with another Luz de la Luna generated and clashes with him in midair before telling Ichigo to fires a Getsuga Tenshō at him. As Ichigo expresses surprise, Ulquiorra points out how this is Ichigo's strongest form and Getsuga Tenshō is his strongest technique before stating he will show Ichigo the difference in their power. Ichigo pushes Ulquiorra away and tells him he did not have to say anything before proclaiming he was going to do this anyway. Generating a large amount of red-black energy around his blade, Ichigo fires a Getsuga Tenshō at Ulquiorra.
The blast hits Ulquiorra, but Ichigo is shocked to see him standing unharmed as Ulquiorra notes this is the level of a Human. As Ichigo notes he is uninjured, Ulquiorra admits that his Getsuga Tenshō closely resembles their Cero, only for Ichigo to deny this and vehemently state the two of them are nothing alike. Hearing this, Ulquiorra deduces that he has not yet seen it and tells Ichigo that he will show him the Cero which the Espada can release while in their Resurrección before firing a Cero Oscuras, which unleashes a large beam of black-green energy.
Hurtling toward Ichigo, the Cero Oscuras completely destroys his mask. As smoke billows from the top of the dome, Ichigo falls to the ground below with his eyes still possessing a Hollowfied appearance and curses. Ulquiorra appears in front of him with Sonído and sends him flying into one of the towers with a slap from his wing. As Ichigo stands among the rubble, Ulquiorra asks him if he understands now and states that the power of Ichigo's techniques are incredibly inferior to the power of Arrancar techniques despite how similar they appear to be.
Ulquiorra begins to walk toward Ichigo while explaining how Humans and Shinigami imitating Hollows will never allow them to become as powerful as Arrancar despite being an understandable route for gaining power. As Ulquiorra appears in front of him, Ichigo gets to his feet, with his eyes returning to normal, before attempting to fire another Getsuga Tenshō. However, an angered Ulquiorra proclaims this is useless before slashing Ichigo across his midsection with Luz de la Luna, which destroys the upper half of the tower which they are inside of.
As Ichigo hurtles out of the tower, Ulquiorra appears next to him before slashing him once more, which sends Ichigo crashing through the side of a tower up to the top of it. Holding Ichigo up by his collar, Ulquiorra demands to know why he will not drop his sword despite seeing the obvious difference in their power. When Ichigo explains how he knew from the start that Ulquiorra was powerful and states he will beat him anyway, a surprised Ulquiorra lets go of him and notes Ichigo's words are those of someone who does not know true despair. Deciding to show Ichigo what true despair is, Ulquiorra enters his Resurrección: Segunda Etapa.
As Ichigo expresses shock at his new appearance, Ulquiorra states this is the form of true despair. Meanwhile, Uryū and Orihime ascend to the hole in the dome via a Reishi platform which Uryū has created. Uryū explains how he remembered using this to travel in the Garganta and only recently realized that he could also create it in Hueco Mundo before noting that it could have had some practical use in battle had he realized it sooner. When he and Orihime sense Ulquiorra's Reiatsu, a shocked Uryū notes it is far more dense and thick than any other Reiatsu he has ever encountered.
On top of the dome, Ulquiorra explains how only he among the Espada can enter this form, which he has not even shown to Aizen. When Ichigo attempts to stand, Ulquiorra asks him if he still has the will to fight after witnessing this form before noticing his hands are shaking. Ulquiorra notes that Ichigo has not lost the ability to feel fear and does not intend to throw away his life before realizing Ichigo still believes he can win. Crouching, Ulquiorra states he will reduce Ichigo to dust in order to make him understand and rushes toward him. Ichigo assumes a battle stance, but Ulquiorra grabs his head from the side.
Ulquiorra throws Ichigo into another tower, destroying the upper portion in the process. When Ichigo attempts to get up, Ulquiorra grabs Tensa Zangetsu before using Latigo to whip Ichigo with his tail, sending him flying back. As Ulquiorra rushes after him and calls him a fool, Ichigo dons his Hollow mask once more before clashing with Ulquiorra, who points out how Ichigo is willingly challenging an opponent so much more powerful than he is that it strikes primal fear into his being, which Ulquiorra finds incomprehensible, before slamming Ichigo through two more towers.
As rubble falls around him, Ulquiorra notes that this must be the work of the heart before telling Ichigo that Humans suffer and die because of this heart. Standing in midair, Ichigo tells Ulquiorra that he is fighting because he has to win and not because he thinks he can win, which Ulquiorra finds ridiculous. Elsewhere, Uryū and Orihime arrive at the top of the dome, where Orihime sees Ulquiorra holding Ichigo aloft with his tail on top of another tower. Noticing Orihime's arrival, Ulquiorra tells her to watch as Ichigo seals off his life and generates a Cero Oscuras. As Orihime screams for him to stop, Ulquiorra fires the Cero Oscuras through Ichigo's chest at point-blank range.
Ulquiorra tosses Ichigo's lifeless body off the tower, forcing a shocked Orihime to catch him with Santen Kesshun. When Orihime attempts to run to Ichigo, Ulquiorra appears in front of her with Sonído and tells her that it is pointless because she cannot hope to save Ichigo's life with the power she possesses. However, Ulquiorra is interrupted by Uryū, who appears behind him with Hirenkyaku before firing a Heilig Pfeil at him. When Ulquiorra deflects the Heilig Pfeil with his wing, Orihime runs past him as Uryū fires several more Heilig Pfeil at Ulquiorra.
Gathering a large quantity of Reishi along his left shoulder, Uryū uses Licht Regen, unleashing a large barrage of Heilig Pfeil at Ulquiorra. As Uryū lands, an unharmed Ulquiorra admits he believed Uryū was the calmest member of Ichigo's comrades, prompting Uryū to say he can fight Ulquiorra because he is calm. Meanwhile, Orihime attempts to heal Ichigo with Sōten Kisshun, but to no avail. Hurtling past Orihime with his left hand missing, Uryū assures her that he has already stopped the bleeding and has applied anesthetic to the wound before taking out a Seele Schneider.
Telling Orihime to take care of Ichigo, Uryū gets up and rushes toward Ulquiorra, who merely slashes him across the chest with Latigo, sending him flying back in the process. Not knowing what to do, Orihime creates a barrier in front of herself with Santen Kesshun, but Ulquiorra shatters it with his tail and continues to advance. Orihime says Ichigo's name over and over in her mind and admits she does not know what to do before mentally asking Ichigo to help her. When Orihime screams for Ichigo to help her, Ichigo's hair begins to grow longer and his arm moves.
Hearing Orihime call his name, Ichigo mentally tells his body to stand up because he will protect her. Orihime turns around to find Ichigo has transformed into a new, humanoid Hollow form, which startles her. Ulquiorra says this is impossible and states Ichigo cannot be alive before demanding to know who he is. Without responding, Ichigo calls Tensa Zangetsu to his hand using Chain before slashing at the ground next to him, which shatters from the force of the attack. When Orihime is sent hurtling away by the shockwave, Uryū reaches out and grabs her.
When Ulquiorra demands to know who he is once more, Ichigo responds by roaring, prompting Ulquiorra to note words are meaningless with him before charging a Cero Oscuras. However, Ichigo leans forward and begins charging a red Cero between his horns, shocking Ulquiorra. As the beams collide, creating a powerful explosion, Ulquiorra flies out of the smoke and expresses disbelief at a Human firing a Cero powerful enough to overcome his Cero Oscuras. However, he is interrupted by Ichigo, who appears behind Ulquiorra before ripping off his left arm as Orihime and Uryū look on in horror.
As Orihime expresses disbelief at this really being Ichigo, a panting Ulquiorra regenerates his arm and explains how most Arrancar trade their ability to regenerate injuries for greater offensive power before revealing he is the only one who can regenerate anything other than his brain and internal organs. Admonishing Ichigo for thinking he can win by ripping off his arm and standing still, Ulquiorra uses Lanza del Relámpago, which generates a green lance with flaming ends between his hands, and tells Ichigo to stay right there, as he does not want to use this at close rang, before throwing it at him, only for Ichigo to dodge it by tilting his head.
The lance hurtles into the desert of Hueco Mundo, where it creates an immense explosion upon landing. Noting he missed because it is very difficult to control, Ulquiorra generates another lance, causing Uryū to realize Ulquiorra can use this attack as many times as he wishes. However, Ichigo appears next to Ulquiorra almost instantaneously, prompting a shocked Ulquiorra to note that Ichigo slipped past his Pesquisa and used Sonído instead of Shunpo. When Ichigo throws his severed arm at him, Ulquiorra disintegrates it with a strike from the lance.
As Ulquiorra tells him to not underestimate him by thinking something like that would catch him off-guard, Ichigo moves to him and grabs the Lanza del Relámpago with his left hand, which shocks Ulquiorra, before crushing it completely, causing it to explode. Ichigo slashes Ulquiorra across the chest, cutting off his left ear in the process. As he falls to the ground, Ulquiorra expresses disbelief at someone like him being defeated by a Hollowfied Human like Ichigo. When Ichigo steps on his head and begins charging a Cero, Ulquiorra states his existence no longer has any meaning before telling Ichigo to do it as Ichigo fires the Cero, creating an enormous explosion.
As the Cero blasts through the dome and hits the ground below as a pillar of energy, shocking the combatants present, Uryū sees Ichigo standing in midair while holding what is left of Ulquiorra by his wing. Tossing Ulquiorra aside, Ichigo begins walking toward him assumes a battle stance with Tensa Zangetsu, surprising Uryū, before holding it over Ulquiorra's head. However, Uryū appears next to him and grabs Ichigo's wrist before telling him this is enough, as there is no need to carve up Ulquiorra's corpse even though he is an enemy, but Ichigo does not respond.
When Ichigo begins to struggle with him, Uryū demands to know if Ichigo can hear him and proclaims Ichigo will lose all of his humanity if he does this. As Ichigo moves Tensa Zangetsu closer to Ulquiorra's throat, Uryū yells his name, only to be interrupted when Ichigo impales him with Tensa Zangetsu. As Uryū flies back, Ichigo states he will help Orihime, who realizes that her cries for help caused this transformation. When Ichigo begins to charge another Cero, Orihime screams for him to stop. However, Ichigo is interrupted by Ulquiorra, who cuts off one of his horns with Luz de la Luna, causing the Cero to explode.
The explosion destroys most of Ichigo's Hollow mask, causing him to collapse as Orihime runs over to him while calling his name. Watching this, Ulquiorra notes that his body regenerating is just for show because the organs which Ichigo destroyed will not return before admitting that he would be dead had he not ended it with the previous attack. However, Ulquiorra is shocked when the remnants of Ichigo's Hollow form swirl around the hole in his chest before fusing with his body and filling in the hole. As Uryū notes the hole has closed up, Ulquiorra recognizes this as High-Speed Regeneration.
Getting up, Ichigo expresses confusion over there no longer being a hole in his chest before noticing Tensa Zangetsu embedded in Uryū's stomach. As Uryū greets him, Ichigo wonders if he did this before being interrupted by Ulquiorra, who notes he is very persistent before moving to Uryū and pulling Tensa Zangetsu out of him. Ulquiorra tosses Tensa Zangetsu to Ichigo and tells him to pick it up so they can finish this. When Ichigo asks him if Ichigo himself stabbed Uryū, Ulquiorra states he does not care, prompting Ichigo to ask him if he also cut off Ulquiorra's arm and leg.
Ichigo tells Ulquiorra to cut off his left arm and leg as well if this is the case before stating that settling this will not be fair unless he is in the same condition as Ulquiorra to begin with. Agreeing to grant Ichigo's request, Ulquiorra is interrupted by his remaining wing bursting into ash, prompting him to ask Ichigo to kill him because he no longer has the strength to walk and will not be able to settle this on his own. However, Ichigo refuses to do so, prompting Ulquiorra to express frustration with him before asking Orihime if she fears him, which she denies.
Ulquiorra wonders what the heart is and ponders whether or not he could find it by ripping open a Human's chest or by smashing open a Human's skull. Noting that Humans speak of the heart very easily, Ulquiorra reaches out to Orihime as his vision begins to fail and states he understands as Orihime reaches for his hand, which dissolves into ash. Looking at Orihime in his final moments, Ulquiorra realizes that the thing in his hand is a heart before completely dissolving into ash, which is blown away by the wind.