Renji Abarai vs. Byakuya Kuchiki

Renji Abarai vs. Byakuya Kuchiki is Renji's second battle of the Ryoka Invasion and Byakuya's first.

Prologue
Renji has escaped from his cell and is beating his way through his fellow 6th Division members to get to Rukia, so that he may save her from her execution. He then senses a strong Reiatsu. He looks to the top of a tower and sees Byakuya on it, looking down at him. Byakuya asks him where is he going. He replies that he is going to save Rukia, and asks if Byakuya will allow him to pass by peacefully, to which Byakuya tells him he won’t allow it.

Battle
Byakuya uses Shunpo and appears behind Renji, but when he goes to attack he is surprised that Renji blocks his attack. Renji notes that Byakuya attempted to use "Senka", which can completely cut off a Shinigami's flow of Reiryoku, and that it's his favorite technique. He comments on how he has seen the move countless times, and after so many times of following Byakuya's movements with his eyes, his body is now fast enough to follow, too. Byakuya remarks that Renji is talking as if he had already won. Byakuya then releases his Shikai, Senbonzakura, but before it can release, Renji stops it with his Shikai, Zabimaru, much to Byakuya's surprise. Renji reiterates that Byakuya's sword can no longer kill him. He tells him that it’s not because he's his lieutenant, but because even before he joined the Gotei 13, the only one he has ever wanted to surpass was him. Byakuya notes that Renji just released his Zanpakutō without calling its name. Before he can finish what he was going to say, Renji releases his Bankai, which resembles an enormous skeletal snake.

Byakuya is somewhat surprised and asks since when has Renji been able to perform Bankai. Renji plainly tells him that he will never know, since he never did care about his subordinates. Renji asks Byakuya again to save Rukia and in return Byakuya tells him that he will not say the same thing twice. Renji goes to attack Byakuya, who uses Shunpo to move to the top of a nearby tower. Renji attacks the towers and only succeeds in knocking Byakuya off, but even then, Byakuya blocks the large Bankai with his Zanpakutō. Byakuya concedes that Renji's power is truly at the level of Bankai, but he feels that it’s time for the battle to end. Byakuya then releases his Shikai, which sends a swarm of tiny blades appearing in the form of cherry blossoms at Renji, destroying Renji's Bankai. However, just as abruptly as Renji's Bankai falls apart, it reconstitutes itself. Renji then explains that he knows the technique of Senbonzakura well, and explains that Zabimaru's segments are connected by his spiritual energy and they cannot be cut apart by knives. Byakuya is noticeably surprised at this revelation. He then slams Zabimaru into the ground, but Byakuya gets away, barely causing him to land in a kneeling position. Renji comments that Byakuya's knee has finally touched the ground and that it is time to end this conflict.

Byakuya gets up and tells him if he wants to put an end to it, it's fine, but the curtain that falls down at the end shall be pulled down by the blade of his sword. Renji defiantly tells him that he has already told him that he knows his sword in and out and the sword that will pull down the curtain will be his, as he goes to attack. Byakuya uses Hadō #33 Sōkatsui, sending a stream of blue fire to cause great amount of destruction in the area, causing Renji to have to use his Zanpakutō for protection. Renji realizes that the move has allowed Byakuya to hide his movements and he goes on the attack again, but Byakuya uses Shunpo to confuse him causing him to lose control of his Bankai. Byakuya then tells him that he is the fool as he didn't use Kidō to blind him, but to disrupt the rhythm of his Bankai. Byakuya tells Renji the biggest flaw of Bankai. He then says that it is too early for him to use Bankai in battle. Renji refuses to give up and says that he knew that, but says his Zanpakutō is not only bulky, but durable as well, and even if it loses one or two segments it can still fight on. Byakuya then uses Bakudō #61 Rikujōkōrō, imprisoning Renji by sealing him with six rods of light. Byakuya then tells Renji to put away his sword and he will live, unless he is still dreaming about defeating him. He then asks Renji if he forgot or if it has never occurred to him that he, too, has Bankai.

Byakuya then releases his Bankai, Senbonzakura Kageyoshi, causing an innumerable amount of giant blades to rise from the ground before they dissipate into countless tiny blades in the form of cherry blossoms, similar to his Shikai. Byakuya then obliterates the building behind Renji with his Bankai, shredding him. Renji falls and Byakuya tells him, in story form, that the difference between them is class.

Byakuya explains the power of his Bankai and tells Renji that he should be proud, as someone who, after being struck by his power, is still able to retain the form of his body. Renji stirs and Byakuya takes notice and tells him not to move as it will only shorten his life. But Renji refuses to give up and begins to stand and lunges at Byakuya, who uses his Bankai technique Senkei, which combines the tiny blades of his Bankai to make them look like multiple swords, incapacitating Renji. He states that he is sure that Renji knows that his Bankai is now gone, and explains that if Renji chooses to get up, he will kill him sooner. Renji tells him that he swore to his soul to save Rukia, and stands. He then runs toward Byakuya, attempting to attack him, but his sword breaks upon contact. Renji falls to the ground and Byakuya takes off his scarf, throws it on top of Renji's body and tells him congratulations, as his fangs actually reached him. He then leaves Renji there.

Aftermath
Renji is grievously injured and left for dead by his captain. Byakuya goes off to attend the execution of his sister Rukia Kuchiki. Renji is later healed by the intervention of the 4th Division's 7th seat, Hanataro Yamada. The fight marks the point where Renji chooses his conscience over his orders. He is determined to get pass his captain and save his childhood friend from an unfair fate. It also marks the moment when he decides to take on the person he has strived hard to be able to defeat, his own captain. Byakuya, for his part, gains some respect from Renji's determination. He also comes to some understanding of the motivation behind those who have come to save Rukia.