The massive metal door began to hiss and whir as the lift came to a stop. Enormous tumblers spun, releasing the lock that sealed this vast darkness away from the rest of the Seireitei. Slowly, the doors opened, creaking and making such a racket that would have been unbearable anywhere but here. Here, the noise was consumed, lost in the endless void of Muken.

Unohana Retsu-she would hang on to that name until the very last moment if she could-stood with her back to the man who emerged from the lift. She took a deep breath as his spiritual pressure, immense enough to fill this empty space, met hers and crowded the air around her head.

"You've prepared quite the stage for us. Good job." His voice barely reached her ears. That was one of the defining qualities of the lowest level of the Central Great Underground Prison. Even two people close together will feel agonizingly distant from one another.

"We meet here by the order of the Captain-Commander." Retsu spoke without turning to face her charge. If she did, she was unsure how long she could hold on to herself as the Captain of the 4th Division of the Gotei 13. Her spiritual pressure carried her voice instead, slicing through the thick fog created by the Eleventh Kenpachi's Reiatsu. "There are no boundaries here. No distractions. There is no better place in any world for you to unleash the full might of your sword."

"Hmph," came his reply, cutting through the fog of spiritual pressure in the same way, "That guy's getting ahead of himself. Captain-Commander or not, no one decides when I get serious but me. It's no fun, otherwise."

The scar on Retsu's chest, a jagged stab wound, ached as he spoke. It always did when he was around. The irritation was especially intense now. "I'm afraid we are not doing this for your entertainment. The Seireitei faces a great threat. It is your duty as a Captain of the Gotei 13 to repel it with all of your strength." A thousand years ago, she would have doubled over laughing at the absurdity of that. Duty had been the furthest thing from her mind back then.

The current Kenpachi cackled, "Hearing you talk about duty really pisses me of. Makes me think you've grown soft over the years. If I wasn't looking at you right now, I'd be sure you weren't up for this. Seeing as you can barely stand still, though, I can tell you're as excited as I am."

Retsu's shoulders jerked. She thought she had managed to keep herself contained, but no matter. It was pointless to try and hide her true feelings from this man anyways. He was the only person she recognized as being truly worthy of the title of Kenpachi. Of course she wouldn't be able to contain herself. "Are you prepared, Zaraki? You've been holding back all this time. Are you sure you remember how to fight with everything you have?"

"You're asking me that question? I didn't come here to fight some motherly nurse from the 4th Division! I came here to take on the True Kenpachi!"

The scar on her chest itched. No, it burned so intensely that the name Retsu was scoured from her soul forever. She was no longer the Captain of the 4th Division. Once again, she was Unohana Yachiru. Her body moved all on its own. She tried to keep her face smooth, but the sides of her mouth crept up against her will. She couldn't stand staring into the darkness of Muken anymore. She needed to see his face. The scar cutting across his eye sent a shiver down her spine almost as much as the ravenous expression on his face. "Tell me, does that scar I gave you nearly a thousand years ago itch?"

Zaraki laughed, "Does it itch? Right now, it's making me want to claw my own face off! I'm sure that hole I put in your chest has you feeling the same way!" He suddenly loomed over her, seeming twice as large with his jagged sword raised over his head. The sheer weight and spiritual pressure contained in that stroke would spell death for most anybody.

But compared to his strength when she first encountered him in the 80th District of North Rukongai, it was nothing. He was more of a boy now than he was then. Weak. And painfully slow. She casually deflected his sword with the back of her hand. The amateur stumbled as momentum dragged him past her. The edge of her blade gently met his vulnerable neck, but failed to take his head as he leaped away. At least his more animalistic instincts were still intact.

That was still not enough, though. He leveled his sword at her in preparation for a counter-attack, leaving himself open once again. She stopped his sword by stepping on his wrist and forcing him to the ground, but he reacted well, swinging his body around and planting a foot in her side. His kick sent her flying, but as soon as her feet touched the ground, she rushed in and slammed her blade into his. Muken shook under a weight that would have leveled the entire Seireitei.

Zaraki put all of his power, or at least as much as he was able to, into the struggle. He bared his teeth and his sword hand trembled under the pressure. It was dreadfully sad. There was nothing left of the mad beast she once knew. Instead, the man who stood before her now was little more than a desperate mouse. Where was his ferocity? Where was his intensity?

"You are weak." It was more of a struggle for Yachiru to keep the deep sorrow from her voice than it was to hold Zaraki's blade back. She took a hand off the hilt of her sword and in the next instant, a knife bloomed from his shoulder with spray of blood. He disengaged, allowing her to send him tumbling. "You insist on using only one arm to swing your sword, and you do nothing with your free hand. Do you not intend to fight with all your strength after all?" She produced another knife from within her sleeve, identical to the one that now jutted out from Zaraki's shoulder.

He pulled the blade from his shoulder and threw it away like a dirty rag. "Cheap tricks like that . . . Don't tell I was wrong this whole time. Were you really so weak?" He charged, pouring a tremendous amount of power into a single wide swipe. That disdainful strike was the most disappointing thing he'd done so far. He was losing his cool after just one unexpected move. Perhaps this was a mistake.

Yachiru stepped forward, driving the knife into his other shoulder. Before Zaraki's eyes could widen she slid the edge of her blade across his chest, starting from his right hip up to his left shoulder. In a single fluid motion she swung around and cut along his waist and back up his right side. Amid a dark red shower, she drove her palm into his chest, sending him crashing against a jagged pillar of stone. His sword stuck into the ground well out of reach. Yachiru strolled up to him and raised her sword, letting the tip of the blade hover just before his throat.

"Do you really think that I am weak?" Her voice dripped with vicious eagerness, daring him to utter those pathetic words once again. If he couldn't see the truth of the situation, then she may as well kill him and leave it at that.

Zaraki breathed through clenched teeth. "Are you saying . . . that I'm the one who's weak? That I've gotten weaker?" His horrified eyes reflected Yachiru's dissatisfied expression back at her. All he had to do was refuse to accept it. He needed to rage against the very idea and shatter the seals he placed on his own strength. "I . . . used to look up to you, you know. Back then, I never had any fun. Everything I cut made me feel the same. It was so boring. I just wanted a good fight . . . and then you came along and pushed me beyond my limits." How terribly sad. Tears slid down the fool's cheeks and his voice quivered, "I wanted to beat you. That's all I-"

Yachiru pushed her sword through Zaraki's throat, severing his spine. Blood came out of his mouth instead of those pitiful words, dripping onto her face. Killing with such a simple, precise stroke was a skill that she was worried she might lose over the last thousand years, but clearly she had no reason to worry at all.

+ Shift +

The pain only lasted an instant before all sensation disappeared. He died without achieving the thrill he always strived for. That was the worst way to go. At least he went out in a respectable way. He was killed by the strongest opponent he ever fought; the only person he was ever truly afraid of. He could be happy with that.

Kenpachi couldn't move or feel his body. He couldn't see, or hear, or smell. He was dead as dead could be, and the final dregs of his beings cried out in frustration. He was killed. What was respectable about that?! He was a sniveling whelp in the very end. How could he possibly be happy with that?!

He had to move. He had to scream! He needed to destroy the version of him that was so weak and pathetic!

"What's wrong?" Kenpachi's eyes shot open. He held his sword, struggling against Unohana's. She looked up at him, spots of blood dripping down her face. "Don't tell me you're falling asleep." The mocking glint in her eyes made his blood boil. With a roar he pushed hard, forcing her back.

Something happened, but he didn't know what. He died, he was sure, but now he was alive again. He was so sure . . . Unohana held out her blade, stalking towards him and oozing spiritual pressure. No time to think. All that mattered now was the fight.

He roared again, meeting his opponent's wave of energy with his own. The Zaraki Kenpachi that let his enemy cut him down while he cried was dead and gone. No matter what he was going to win. He was going to do what he set out to do a thousand years ago and kill this monster woman.

Raising his jagged sword over his head, he poured every ounce of power he had into a single strike. No Zanpakuto was unbreakable. They were just swords in the end, no matter what others said about speaking with the spirits within the blades. They were objects, and Zaraki Kenpachi never saw an object he couldn't destroy with his might!

Unohana's sword slid into his waist and cut deep, nearly separating his waist from his torso. Darkness filled his vision and the mass exodus of blood left the parts of his body he could still feel cold and unresponsive. He wasn't strong enough after all.

A rush of air filled his lungs as his eyes shot open. He was careening through the air head over foot. Why was this happening? If he kept blacking out, he really was going to die. Digging his fingers into the ground, he righted himself and charged back into the fight. Whatever it was, he could figure it out after the fight was over.

All of his focus centered on Unohana. The world around them faded into nothing. The ground, the walls, sparsely placed pillars; all of it melted away easily. Muken really was the ideal place to do this. A surge of power drove him forward, slashing in as loose a pattern as he could devise. For the first time, she retreated, pushed back by his barrage. Yet he still couldn't land a hit! He roared, frustration driving him even further, until his sword arm flew into the air and Unohana's blade ran him through.

Darkness.

Eyes open! She was rushing towards him now. Bearing down with a series of well placed strikes, she nicked and cut him, but the wounds were shallow. He wasn't being bold enough! Watching her carefully, he opened himself up. An obvious trap, but one that would be most effective in the heat of battle. The tip of her sword slipped between his ribs. Instead of back away, though, he stepped into it, locking her into place unless she abandoned her sword. Ideally, she would have tried to back away, but she pushed on, messing with the distance of his strike. His blade caught her shoulder, leaving a small, but jagged cut. That wasn't good enough! A blast of energy opened a gaping hole in his chest.

Darkness.

He stomped down, preventing her retreat by pinning her foot. She was faster than he was, no doubt, but they were on equal footing in terms of strength. He could outlast her. He would outlast her! Blood spewed from his mouth, coating his chest as he fell back.

He reached out with his free hand, stopping her sword mid-swing. He took aim at her leg, hoping to cripple her, but then his head tilted back involuntarily. A fountain of blood from his own neck doused his face. He jumped back deflecting a thrown knife and let Unohana come to him. He'd catch her in an opening this time. When she leaped into the air, blade pulled back for a wide swing, he licked his lips and jumped up to meet her. He should have been able to cut the unguarded half of her body, but the force of her strike sent him crashing down, crushing his lungs with the sheer force of the blow.

Again and again he blacked out and awoke to continue the fight. Whether those repeated visions of his death were real or not, he continued to fight with all he had. It didn't even occur to him to question. Why should it, when he was having this much fun!

+ Shift +

Yachiru held her hand over Zaraki's lifeless body once again and bathed him in her Reiatsu. She had no affinity for Kaidō, truth be told. Her specialty was ending life, not preserving it. Only by the merits of Kirinji Tenjirō's healing techniques was she able to stand as the Captain of the 4th Division. Without her peerless spiritual pressure alone, she wouldn't be able to heal a bruise, let alone revive a dead opponent.

It was funny in a morbid kind of way. Her whole life had revolved around proving that she was the strongest. When she met Shigekuni, she thought she had found the closest thing to an equal that could ever exist. His sword techniques were ultimately lacking, but the sheer destructive force of his Zanpakuto posed a real challenge. Had its output not been tied to a life she could easily end, she may have bowed her head to that sword. It was not until she was sent to Zaraki, the Rukongai's 80th district, that she truly met someone that stood above her.

He was just a boy, a feral child standing atop a mountain of corpses. He had no special traits or clever tactics, but when he swung his sword at her, she could feel the world-shattering power of his spirit. That was the first and only time she'd ever fought for her life. He could have killed her then, the difference in their strength was that great. She should have died, but she wasn't strong enough.

Zaraki roared as his senses returned and the fight continued. He was getting faster, introducing more variety into his attacks and utilizing his entire body to assault her. It still was not good enough, however. She flicked her wrist and Minazuki's edge slid through his abdomen. She waited a moment for death to descend on him before beginning the healing process.

This was all her fault. If she had been strong enough to pose a threat to that wild boy a millennia ago, none of this would have been necessary. Because of her weakness compared to him, he began to hold himself back. That poor, terrible child sealed his own strength to preserve the bliss of a good fight for as long as possible. Among all of the atrocities she committed, failing to provide that thrill to a young Zaraki was her deepest sin. Mastering Kirinji's healing techniques was the only way she could see to repent for that failure. If she could not kill him at his full strength, then she would ensure that he lived until she could die by his hand, his full strength restored.

He rose again, and she cut him down. Over and over. She would spill his blood a thousand times and more. She would flood the streets of the Seireitei with it if she had to. All in the hopes of awakening that dormant power. Faced with life or death battles until he remembered how to use that jagged blade of his.

She slashed him, cleaving through his shoulder and cutting across his chest. Blood sprayed from the wound and he stumbled, falling back. But he didn't fall. Planting his feet he steadied himself. He was smiling. A wild sort of smile filled with the bliss of combat. His body moved before she could react. He dragged the jagged edge of his blade across her chest, spilling a great deal of her blood for the first time. The searing pain of her flesh being torn opened her eyes. Zaraki's training was progressing much faster than she expected. She felt her mouth tilt up in a smile that she was once feared for.

Fixing her stance, she parried his attack and pushed him back with a shallow cut across his face. He looked stunned that she was still standing. She couldn't help but laugh. "Did you think you had killed me? You are much too naive." Yachiru quickly waved a hand over the open wound and it closed seamlessly. "Learning Kaidō had a great many unforeseen benefits. Did you know that I was never able to utilize my Zanpakuto's full potential before becoming a master of the healing arts?"

Zaraki kept his distance and watched her cautiously. A wise decision. She did not truly believe that she could have beaten him a thousand years ago, even with this technique, but it was a good sign that he could sense the danger.

"Bankai." There was no way to keep the excitement from her voice. Minazuki's true form was rightfully deemed too dangerous to use in most combat situations. Thus, even after learning the healing techniques that allowed her to use it as she desired, she hadn't had a chance to actually fight with it. "We will be moving on to the final lessons now."

Minazuki's edge dripped with a dark red acid that pooled at her feet. If it were not so potent that it ate a trench into the ground she would have had to constantly repair her feet before she sank into the sludge. The sound of her skin sizzling as she dragged the tip of her finger along the back of the blade made her heart beat almost as fast as the prospect of fighting Zaraki at his full strength did.

His face contorted into a frenzied mask, a reflection of her own feelings, and he roared. They clashed and the foundations of the Muken trembled.

+ Shift +

The ooze from Unohana's Zanpakuto filled Kenpachi's vision. He felt his body hit the ground. He was standing again, clashing swords. That red ooze splashed onto his chest. His sword arm fell off and his body collapsed in on itself. He drew back for another strike. This time he would break through! His arm fell off again and his head tumbled from his shoulders.

He laughed as he fought. More than he had in a long, long time. He was being melted. Over and over again his skin and muscles were being eaten away by that blood red sludge. He pretty much figured what was happening a while ago. A guy can only die so many times before he realizes he's been dying and getting brought back to life. All those deaths before were caused by his own weakness and lack of skill compared to his opponent. But this was something else entirely. The corrosive gunk coming from Unohana's sword was so potent that touching it for even a moment allowed it to melt him away. Dying to that was no matter of skill. It was an invincible offense on a level he'd never seen before.

So why was he still having so much fun? Getting to fight and fight and fight with no regard for his own life was good fun, but this was different. This was bliss! But why?

Again and again he met her sword. Again and again he was reduced to nothing but bone. But that feeling of ecstasy never subsided. As his face melted away for the umpteenth time, his eyes took in the image of his opponent and he understood.

The first and only true Kenpachi was fighting with her life on the line as well. He witnessed the acidic sludge coat her skin and reduce her to bones the same as it was doing to him. At the same time she healed them both, maintaining their lives through death. It was thanks to her efforts that they could enjoy this ecstatic exchange.

This whole time, it was like he was sleepwalking. He was content with the dream of a good fight. His meeting with Kurosaki Ichigo, his encounters with the Arrancar, even that Quincy bastard that beat him, were nothing. Crossing swords with those guys was like smacking each other with sticks. This is a battle between two warriors driving themselves beyond death to find out who was superior.

This is a fight!

+ Shift +

Only one person may hold the title of Kenpachi at a time. This is an immutable rule, a law given credence by the strength of those who abide by it. The title changes hands only when the holder is defeated by someone who is stronger.

The history of the name Kenpachi was fraught with pretenders and weaklings. Persons that would attain the title and simply let it pass when it became apparent that their lives were tied to the name. Of the eleven to hold that title, most were strong and held onto the title until it was taken along with their lives. Some were weak, but clever enough to attain the right to call themselves Kenpachi. None held that title legitimately. Because none of them had ever defeated Unohana Yachiru.

She felt nothing when the first pretender claimed the title. He was strong. Enough to defend his claim in her absence. She felt nothing when that man was poisoned and a truly pathetic weakling took the credit for his defeat. It was a fake title. Perhaps that was why she didn't bat an eye when the name Kenpachi passed to three more people in the span of a year. Or perhaps she didn't care because she believed that one day the true successor would appear and grab hold of his rightful position.

When Zaraki Kenpachi ripped the title and the position of Captain of the 11th Division from the 10th holder, she had celebrated with a particularly high quality sake. The flustered look on Isane's face when she asked her to sit and join her was a precious memory. She was going to miss those little moments.

Yachiru leapt and spun, coating the entire area with Minazuki's acid. Zaraki dove through the corrosive spray fearlessly in pursuit. Not to be outdone, she concealed herself behind an acid curtain, then lunged through it. They were both skeletons by the time their swords met, but they continued fighting. She could not have anticipated the depths of her gratitude towards Kirinji Tenjirō for teaching her the healing techniques that made this fight possible.

Zaraki's face was losing that wild look it had, but that wasn't a bad sign. Yachiru felt the muscles in her face relaxing too. The thrill was not dissipating. If anything, it was becoming more intense. Assuming he felt the same way, she suspected this feeling would be called satisfaction.

One of Yachiru's happiest memories was that rainy day a thousand years ago. This man bearing down on her was just a boy. He laid unconscious, a pool of blood spreading from a wound he sustained in the fight with her. She was happy, looking down at him, motionless there. Not because she had emerged victorious-she could never feel joy defeating an opponent who was holding back-but because she had found a successor; someone who would one day take the title of Kenpachi from her.

Isane was going to be sad. That made her feel a little guilty about feeling so happy about this.

The moment Zaraki's body was restored, he pushed his blade through Yachiru's chest. He did it. He landed a decisive blow by his own power. He had without a doubt surpassed her. The monster that had made her so happy back then had finally returned.

"Well done. This marks the end of your training. I recognize you, Kenpachi from Zaraki." She was so happy that the darkness creeping in from the edges of her vision didn't bother her. Neither did the loss of feeling in her limbs. The sound of Minazuki falling to the ground as her fingers lost strength was tremendously satisfying. When Zaraki pulled his sword from her chest and threw it into the darkness behind him, she didn't feel it. That was a little sad. She had hoped to experience her defeat in its entirety, but even her body couldn't overcome the creeping of death.

She tried to heal herself, but her spiritual pressure had already dropped to low. She only had enough energy left to see and that was fading quickly.

Zaraki supported her body as it went limp. He seemed to be saying something. He looked desperate, like he was pleading with her. He was crying. For her. What an amusing child. He had every right to be sad. She would feel the same were the situation reversed. That was the responsibility of the victor, and the burden he would have to carry as the strongest. Things were going to be boring for him, but he'd have to put up with it until a proper successor appeared before him.

Kenpachi was the heaviest title any person could hold, but that crushing weight was nothing for the strongest.

+ Shift +

She was gone. He beat her. He defeated the one true Kenpachi. That would make him the Kenpachi now. For real, this time. It wasn't just a placeholder to fill in for his lack of a proper name. He was happy. His strength-his true strength-was finally recognized by the one person that mattered the most. So why did he feel so lonely?

Was he truly alone now, standing at the pinnacle as he was? Was anyone even close to matching him anymore? There had to be someone who could hold their own against him. The world wasn't such a bleak place that there wouldn't be anyone who could give him some semblance of a fight.

He told himself that, but she was gone. The one person that gave him a proper fight was dead. He was alone.

You aren't alone.

Kenpachi's hackles rose and he turned to face the darkness of the Muken. He couldn't feel anybody else down here, but he definitely heard a voice.

Kenpachi . . . Zaraki Kenpachi . . .

"Who's there?! Quit hiding and face me!" He shouted into the infinite depths of the lowest level of the Central Underground Prison, but no response came. The voice he heard . . . it felt familiar somehow. He didn't remember ever hearing a voice like that before, though. He scanned his surroundings for several quiet seconds before the voice spoke again.

You can hear me? You can finally hear my voice?

There was no hostility in that voice. If anything, it gave him a feeling akin to camaraderie. "Who are you?"

I'm the one who has been with you longer than anyone else. I've been watching you all this time, even though you could never hear me before.

The more he heard it, the more his eyes were driven to the owner of that voice. His focus settled on the jagged sword sticking up from the ground where he tossed it. His sword. His Zanpakuto.

It's nice to meet you properly, Zaraki Kenpachi. My name is . . .