Help! I am bound to Aizen!

A Shinigami's durability was generally extraordinary.

For an ordinary human, being pierced through or sustaining a large gash would likely be fatal. But for a Shinigami, such "fatal injuries" were just another day's work—treatable with a bit of healing.

Take, for example, a certain well-known tank of the Fifth Division in later years: stabbed multiple times, yet he emerged from the hospital as energetic as ever.

Aizen understood this well. He used Kyōka Suigetsu to confuse Goken Kenpachi, not to kill, but to destabilize the battle and tip the scales further in his favor.

But then, something shifted. 

The moment Goken left an opening, Kaelith Yurei's presence transformed. The dangerous aura he radiated was so intense that even Aizen, rarely surprised, glanced at him.

Kaelith's eyes locked onto a precise spot on Goken's Zanpakutō. His pupils narrowed as if focusing his entire being on the target.

And then, his fist shot forward.

The punch landed squarely on the blade.

*One layer!*

Simultaneously, a shadow perfectly synchronized with Kaelith's movements delivered an identical strike.

*Two layers!*

**Double Layer · First Bone!**

*Boom!*

A wave of white Spirit Pressure exploded outward, forming a long, streamlined blast that extended for kilometers, leaving a massive, rippling trail of destruction in its wake. 

Under Aizen's astonished gaze, Goken Kenpachi was blasted backward like a cannonball, slamming into a distant mountain. The impact created a crater as massive fragments of rock, coated in dust, scattered across the landscape.

Aizen's gaze lingered on the steam rising from Kaelith's fist. Suddenly, something clicked.

"This... is that stacking technique you mentioned earlier?" Aizen asked, his tone intrigued.

Kaelith exhaled deeply, steadying the chaotic Spirit Pressure surging within him. 

"It's similar in principle," he explained, "but I used a shortcut by leveraging my Zanpakutō."

As he spoke, Kaelith raised his hand, inspecting it briefly. 

This time, he had intentionally restrained part of his strength, avoiding the full-force recklessness of his previous attempt. The results were promising—his injuries were far less severe.

At worst, his muscles were slightly torn, and two of his finger bones had minor fractures. 

Such injuries wouldn't even require a Hell Hot Spring treatment—Captain Unohana could patch him up with ease.

Realizing this, Kaelith mused that perhaps it was time to study some basic healing techniques himself. 

"I can't always drag Fourth Division medics into every fight."

While considering this, he reached out toward his Zanpakutō, which was lodged in the ground some distance away.

From beneath the blade, a shadow flickered.

*Swish!*

The Zanpakutō launched into the air like a projectile from a catapult, spinning before landing neatly in Kaelith's hand. 

Holding the sword, Kaelith made a dramatic slash in the air and struck a pose.

"How's that, Aizen? Cool, right? Remote sword retrieval—pretty stylish, don't you think?"

Aizen gave him a sidelong glance, silent.

He wanted to tell Kaelith that if he truly wanted to be stylish, he should consider going the rest of his life without speaking. 

But knowing Kaelith, there was no way he'd manage that. Aizen decided not to waste his breath.

The two used Shunpo to reach the location where Goken Kenpachi had landed.

Aizen waved his hand, dispersing the lingering dust and revealing the scene below.

His pupils contracted slightly at what he saw.

Goken Kenpachi lay in the crater, his face frozen in disbelief. 

His eyes were locked on his Zanpakutō, where a deep crack was visibly widening.

*Crack. Crack.*

Goken Kenpachi's hands trembled as he desperately poured Spirit Pressure into his Zanpakutō, trying to stabilize it.

Aizen shot Kaelith Yurei a deep glance. 

In its Bankai state, a Zanpakutō was incredibly durable, nearly indestructible—one of the hardest substances in existence. Any damage inflicted while in this state was permanent and irreversible. The blade would be damaged, and the Shinigami's power would diminish as a result. 

And yet, Kaelith had just punched the Bankai-state Zanpakutō and broken it?

Sensing Aizen's thoughts, Kaelith smirked and shook his head. "That punch wasn't as miraculous as you think. Our relentless attacks wore the blade down, causing metal fatigue. That final blow? Just the last straw that broke the camel's back."

Aizen: "…"

Choosing to ignore Kaelith's shameless remark, Aizen approached Goken Kenpachi. 

Perhaps the presence of Aizen unsettled Goken, disrupting his concentration. A loud *snap* echoed as the blade fractured completely, breaking into two jagged pieces.

Staring at the remnants of his Zanpakutō, Goken let out a wretched, guttural scream. 

Aizen's gaze hardened as he watched the pathetic display. For someone who had clawed his way to a captain's seat, however unworthy, Goken could have at least maintained a shred of dignity. 

And then, as if struck by an epiphany, Goken's expression shifted. A strange grin spread across his face.

"Forget it. I'm not leaving," he said, his voice chilling. 

"Without my Bankai, I'm nothing more than a disposable pawn if I return. So I'll make sure you both experience the same despair as me!"

Before Aizen could react, Goken vanished, his figure blurred by his sudden burst of speed.

Aizen turned sharply, his eyes narrowing as he realized Goken's target—his laboratory. 

At the same time, Goken's Spirit Pressure surged dramatically, climbing toward its limit. Aizen immediately understood his intention: Goken intended to destroy the lab.

If Goken succeeded, it would be disastrous. Not only would Aizen's painstakingly crafted projects be obliterated, but the lab's existence would be revealed to the Seireitei. 

The lab was rife with evidence of Aizen's handiwork. The Second Division's investigators wouldn't need long to link the lab back to him.

Without hesitation, Aizen launched into flash step, pursuing Goken at full speed. 

His blade struck Goken's back, leaving a deep, bloody gash. But Goken, fueled by sheer willpower, ignored the pain and pressed on, closing the gap to the lab.

Less than ten meters remained.

Goken's Spirit Pressure had peaked, his body vibrating with unstable energy. A twisted grin spread across his face as he prepared to detonate.

And then it happened.

An invisible force slammed into him from above.

*Schlurk!*

An unseen blade pierced Goken's heart, stopping him in his tracks. 

Aizen's surprised gaze shifted to Kaelith, who landed next to Goken. 

"...You already took one hit like this, and you still didn't learn?" Kaelith muttered, retracting the invisible blade. 

He raised his Zanpakutō, preparing to end Goken once and for all.

"Wait!" Aizen interjected, rushing over.

Stopping Kaelith's strike, Aizen quickly executed a series of high-level Kidō spells, sealing Goken and preserving his last breath. Finally, with the work done, he exhaled in relief.

A perfect high-level experimental subject like Goken was a rare find. Letting him die would have been a colossal waste.

Straightening, Aizen glanced at Kaelith, who was watching him with a curious expression. Then his eyes shifted toward the now-exposed laboratory, where much of his equipment and experiments were plainly visible.

A complicated expression settled over Aizen's face.

"This… is bad."