Ichigo Kurosaki vs. Ulquiorra Cifer

 is a battle taking place during the Invasion of Hueco Mundo between Ichigo Kurosaki and Espada #4. Ulquiorra Cifer, acting as the first direct confrontation between the two.

Prelude
While running through a corridor in Las Noches, Ichigo Kurosaki stops in shock with Nel Tu under his arm upon sensing the drop in Rukia Kuchiki's Reiatsu following the conclusion of her battle against Aaroniero Arruruerie, which leads Ulquiorra Cifer to admit that he underestimated Ichigo's senses due to believing the latter was just a boy with a lot of Reiryoku while appearing on the steps behind Ichigo and noting that it has been a while since they last met.

As Ulquiorra walks down the stairs toward him, a stunned Ichigo identifies him by name, prompting Ulquiorra to note that he does not recall introducing himself to Ichigo prior to reaching the bottom of the steps and informing the latter that Rukia is dead, to Ichigo's shock. Ulquiorra elaborates that Rukia and Aaroniero killed each other and asserts that she is quite dead due to a trident being thrust through her abdomen, and when Ichigo accuses him of lying since her Reiatsu only just dropped and questions how he could know this since he did not fight her, Ulquiorra reveals that Aaroniero had the ability and duty of Cognition Synchronization, which allowed him to instantly relay data about any enemy he was facing to all of his comrades.

Upon learning of this, Ichigo walks away from Ulquiorra and tells the latter that he is going to save Rukia upon being asked. Despite Ulquiorra reiterating that Rukia is dead, Ichigo refuses to believe him, leaving Ulquiorra to accept this and question why Ichigo is not killing him first. In turn, Ichigo observes that he has no reason to kill Ulquiorra, to the latter's confusion, and points out how he has not hurt any of Ichigo's friends yet even though they are enemies, but Ulquiorra reveals that he is the one who brought Orihime to Hueco Mundo.

Fight
In turn, an angered Ichigo puts down Nel, immediately attacks Ulquiorra with his Shikai, Zangetsu, and confirms that Orihime did not come here of her own free will after all, though Ulquiorra merely blocks this with his wrist and comments on how interesting it is that Ichigo came all the way here to save Orihime even though he was not sure of her innocence. When Ichigo demands to know if Ulquiorra knows that everyone believes Orihime is a traitor because of what he did, Ulquiorra affirms this as being exactly what he intended and wonders if Ichigo has a reason to fight him now. With Nel huddling down and sheltering herself from the intense clash, Ichigo disengages from Ulquiorra to tell her to stay back and observe that they are going to do this the hard way prior to asserting that he will not hold back because he is in a hurry.

Ichigo activates his Bankai, Tensa Zangetsu, and leaps out of the resulting surge of Reiatsu. Despite being unfazed by this, Ulquiorra is startled to see Ichigo wearing his Hollow mask just before the latter comes down on him with a Reiatsu-infused strike of his sword, forcing an unnerved Ulquiorra to block this with his wrist once again. Ichigo slashes his sword forward, sending Ulquiorra flying back and crashing through several pillars. Upon landing on the side of a pillar with his feet and questioning why Ichigo is so akin to the Arrancar with his mask and Reiatsu, Ulquiorra sees Ichigo firing a massive Getsuga Tenshō at him and attempts to stop it by grabbing the blast with his right hand. However, the Getsuga Tenshō continues pushing him back even after he grabs it with his other hand, and a nonplussed Ulquiorra is engulfed in an enormous blast as the energy overwhelms him.

Following this, an exhausted Ichigo stands in the clearing dust as his mask shatters and falls off his face in pieces. When Nel calls out to him, Ichigo turns around in relief, only for Nel to slam headlong into his face with enough force to slam him against a pillar several meters away and lament that she thought Ichigo was going to be killed, with Ichigo confirming that he believed Nel would do this. Nel admonishes Ichigo for using so much of his power when already injured and tells him to never do this again before crying into his chest, leading Ichigo to apologize to her and begin getting to his feet so they can get going.

Suddenly, after Ichigo assures Nel that he is fine and they just have to hurry, Ulquiorra emerges from the cloud of dust behind him with only a few light scratches, to Ichigo's astonishment, and admits to being surprised since he could not stop that attack even with both hands. Questioning if this was the best that Ichigo had, Ulquiorra infers from Ichigo's stunned gaze that it was and holds up his right index finger as he calls this unfortunate. With Ichigo realizing what he is about to do, Ulquiorra fires a Cero that engulfs Ichigo and Nel, sending the former crashing through the far wall onto the sands outside with burns and blood covering the left side of his body while carrying an unconscious and injured Nel. When Ichigo attempts to move back inside to tend to Nel, Ulquiorra appears next to him with Sonído and delivers a powerful kick to Ichigo's side, resulting in him smashing into the upper portion of one of the nearby leaning towers.

As Ichigo struggles to catch his breath, Ulquiorra joins him in the tower and observes that Ichigo quickly summoned his Hollow mask again when blocking the Cero, but recalls that it shattered immediately and concludes that Ichigo will not be able to generate it again before telling Ichigo to give up. In response, Ichigo stabs his sword into Ulquiorra's left shoulder and refuses to ever give up as he declares that defeating Ulquiorra will effectively end the war since the latter is obviously the most powerful Espada. However, Ulquiorra simply calls this unfortunate and grabs Ichigo's sword by the blade to pull the left half of his coat to the side, exposing his tattoo of the number 4 on his left pectoral and clarifying to an aghast Ichigo that he is only Espada #4. Ulquiorra shoves his left hand into a stunned Ichigo's chest and bluntly states that the latter cannot defeat him. Noting that there are three Espada stronger than he is even if Ichigo could do so, Ulquiorra pulls his hand out of Ichigo's chest, leaving the latter to collapse, and concludes that there can be no victory for him here.

Aftermath
Standing before an unmoving and heavily bleeding Ichigo with his left hand coated in the former's blood, Ulquiorra observes that he overestimated Ichigo's strength. After asserting that this is the end for Ichigo, who remains unresponsive, Ulquiorra orders him to leave Hueco Mundo immediately if he can still move and to die if he cannot because his quest is at an end while exiting the tower, leaving Ichigo to continue lying motionless as Tensa Zangetsu automatically dissipates and returns to its Shikai state. Some time later, a battered Nel crawls over the rubble to find Ichigo lying motionless in a pool of his own blood, causing her to begin crying as she drops to the floor and pulls herself over to Ichigo, whom she repeatedly begs to not die. However, Nel finds her path blocked when Grimmjow Jaegerjaquez appears in front of her and tells her to get out of the way.