Kenpachi Zaraki vs. Tenken & Gonryōmaru

 is a battle that takes place in the Zanpakutō's cave during the Zanpakutō Rebellion, between 11th Division Captain Kenpachi Zaraki and the Zanpakutō Spirits, Tenken and Gonryōmaru.

Prelude
After finding Captain-Commamder Genryūsai Shigekuni Yamamoto's Reiatsu, Yoruichi Shihōin organizes a search team to go rescue him. As she explains the situation to Captains Jūshirō Ukitake and Shunsui Kyōraku, Captain Zaraki and Lieutenant Yachiru Kusajishi listen on. Yachiru pleads with Kenpachi to go, but he says that they are not playing hide and seek. Kenpachi asks Yoruichi if he will be able to fight someone if he goes and she responds that it is highly probable but reminds him not to attack the Captain-Commander by mistake. Kenpachi laughs, stating that Yamamoto would not die from an accidental attack on his part. After Ukitake and Kyōraku also agree, they head off to the cave.

Once there, Ukitake senses Yamamoto's Reiatsu and the presence of a barrier, leading Kyōraku to believe that not even Muramasa could control Ryūjin Jakka. Kenpachi gets excited and asks if Yamamoto is really in the cave. Yoruichi says there is no denying it, but the cave is like a maze. Yoruichi says that they will need to be cautious since this is the enemy's main hideout. Kenpachi smiles, telling them that they should just kick their doors down as he begins to enter the cave with Yachiru on his shoulder cheering him on.

Kenpachi wanders around in the cave in complete darkness. He says he was going to charge right in, but he cannot even see his hand in front of his face. He asks Yachiru which way they are going, but she simply responds "that way", prompting him to say that he cannot tell which way that way is. Yachiru angrily says that that is why she said "this way", as Kenpachi yells for her to stop pulling on his ear. He finally reaches a lighter passage when Tenken and Gonryōmaru appear from above. Kenpachi laughs, muttering that they finally came out and that now he doesn't need helping luring them out. Gonryōmaru says he is amazed that Kenpachi has made it this far but now it is time for revenge.

Battle
Kenpachi clashes with Tenken, grinning as he does so. He begins to overpower the giant Zanpakutō Spirit, telling him that it is time to die and slashing across, forcing Tenken to dodge. Gonryōmaru tries to attack Kenpachi from behind, but he intercepts this movement, sending him flying backwards. Kenpachi taunts Gonryōmaru, asking why he has not exacted revenge yet. He asks for Gonryōmaru to give him something he can work with and Yachiru pops out to taunt Tenken, saying he can't beat Kenpachi if he doesn't attack. Kenpachi tells Yachiru to stay out of it though. She says that it is true though and that they aren't even a challenge, almost as if they weren't trying. Kenpachi tells her to just sit and watch but realizes Yachiru has a point. He asks the Zanpakutō Spirits if they are even trying to kill him. Gonryōmaru says that sometimes you achieve victory by simply not losing. Kenpachi asks if they have already accepted defeat, raising his Reiatsu.

Kenpachi cuts Gonryōmaru down easily, reverting him back to his sword form. He tells Tenken not to worry about the other leaving as he will be staying right there. He clashes with Tenken repeatedly as Yachiru watches on. As Tobiume throws a fireball at Yoruichi elsewhere in the cave, Kenpachi feels the blast hit the wall, realizing the others are fighting too. Yachiru asks if he thinks Ichigo is okay, but he states that, whether he is alive or not, he will fight him or whoever kills him once they get out of the cave. He reverts his attention back to Tenken who throws his whip at Kenpachi, but he knocks it away with ease. Kenpachi lunges at Tenken, knocking him back before lashing out wildly at him. Tenken holds his ground and strikes back with a powerful swing, but Kenpachi catches it with his bare hand.

He tells the Zanpakutō Spirit that it is about time he faced him seriously. He says he has known all along that he was holding back because he was worried about his friend, but now he has no one to worry about and that it is time for the real festival of blood to begin. Kenpachi unleashes a surge of Reiatsu as a heavy wind envelops the area and Yachiru smiles with glee. Tenken counters with his own surge of Reiatsu, causing Yachiru and Kenpachi to get excited. Yachiru says that he is finally getting serious, as Kenpachi tells her she should get out of there. Tenken then unleashes his Bankai transforming him into the giant of his master's Bankai, breaking through the top of the cavern. Seeing this prompts Kenpachi to burst out laughing in excitement. He says he hopes the massive body is not just for show. Tenken prepares to swing at Kenpachi, who surges his Reiatsu, catching the sword with it, jumping up to face his opponent.

Worn out now, Kenpachi tells Tenken to make his next move. After Tenken does not comply he jumps up again to attack the giant. Tenken swings his sword at Kenpachi who attempts to block with his own sword, but is thrown back into the wall by the resultant force. He falls to the ground and Yachiru yells out for him. Still smiling, he tells Yachiru to pipe down. He commends Tenken's fighting ability, stating that he can now enjoy the fight. Tenken swings his sword down at Kenpachi who blocks with his own, but the tremendous force, causing him to sink into the ground below. Kenpachi gets up, knocking Tenken's sword away with his Reiatsu, saying that it was a fine attack, but it was not good enough. He then jumps up and cuts one of Tenken's horns off, stating that it is not over yet.

Aftermath
In the Human World, Muramasa manages to free Kōga Kuchiki and the Shinigami and the Zanpakutō unite to stop him, leaving the result of this fight unknown.