Muken—a place where countless once-glorious figures have been imprisoned.
Most of them are here because they committed unforgivable crimes. Among them, the majority are former captains of various divisions. They possessed immense power and lived through countless years. Over such an extended period, even the slightest wavering of will or the birth of heretical thoughts could lead to grave offenses.
Yet, because of their overwhelming strength, executing them outright wasn't an option. Instead, they were locked away in this prison.
It didn't take long for Masatsuki Aozaki to lock onto his first target—
A man who looked utterly worn out.
His wrists and ankles were bound by heavy shackles, his body restrained near a massive pillar. His movements were limited to a mere three-meter radius around it. His disheveled hair hung over his shoulders, his tattered clothes barely clinging to his body, and his vacant eyes remained cast downward.
Masatsuki Aozaki didn't recognize this man, but the faint traces of captain-level Reiatsu lingering around him made one thing clear—before his imprisonment, he must have been a prominent figure.
As Masatsuki approached, the man seemed to sense something. Slowly, he opened his weary eyes, gazing at him in confusion. Then, upon seeing Masatsuki's composed and effortless demeanor, his face revealed a hint of surprise.
Under normal circumstances, the only ones who could enter Muken were:
Criminals like him—powerful beings guilty of heinous crimes.
Members of the First Division's special forces, clad in uniform, responsible for patrolling the prison.
Or the high-ranking officials of Seireitei who wielded authority.
But someone like Masatsuki Aozaki, dressed in a black cloak, clearly didn't fit into any of these categories.
A man lurking in the shadows—he could be nothing but trouble.
"You..." the man muttered instinctively.
The outer walls of this prison were constructed with Sekkiseki, blocking the flow of Reishi. Inside, layers of barriers were set up, restricting both the space and the prisoners themselves. This design ensured that inmates remained as powerless as possible.
Though the man seemed relatively unrestricted, in truth, he couldn't even exert a tenth of his former strength.
And yet, the black-robed figure before him—unshackled, moving freely through this space as if completely unaffected—was clearly someone formidable.
Who is this guy...?
A flicker of fear crossed the man's eyes, but it was quickly replaced by excitement.
Masatsuki Aozaki, however, gave him no time to think. With a slight shake of his head, he vanished in an instant.
A sharp pain shot through the man's chest.
His eyes widened, pupils contracting in shock.
So fast!
Even in a place like this, someone could move that fast?
He hadn't even seen it happen.
Looking down, he saw a pale hand piercing straight through his chest.
Agonizing pain twisted his expression.
"Sorry, I'm in a hurry," Masatsuki Aozaki said, his voice devoid of emotion.
The man's face contorted in disbelief.
He had assumed this intruder had come to Muken for some kind of scheme. Maybe even to create enough chaos for an escape.
After all, he had been imprisoned for slaughtering nobles—a crime considered absolutely unforgivable in Seireitei.
A six-thousand-year sentence. Practically no different from a death sentence.
For a brief moment, a glimmer of hope had sparked in his heart.
But now, that hope was instantly crushed.
He never imagined that the reason this man had come... was to take his life.
An enemy?
How?
He had been locked away for centuries—who would still hold a grudge against him?
Unless... had he failed to kill all his enemies before he was imprisoned? Had someone survived?
Masatsuki Aozaki said nothing. He simply withdrew his hand.
Resting in his palm was a bead, glowing with a brilliant green light.
"I haven't done something like this in a long time... Feels like my technique has gotten rusty."
Masatsuki Aozaki gazed at the lifeless man before him and let out a soft sigh.
With a casual wave of his hand, an ink-black Schatten Bereich rapidly unfolded.
Given his abilities, once he understood the principles, replicating the Wandenreich's shadow space was no challenge. Masatsuki placed the man's soul inside. Then, he turned his head and shifted his gaze to the other side, his tone calm.
"This should be our first real meeting, shouldn't it?"
"You've been enjoying the show for quite a while now. Isn't it about time you stepped out and showed me your true face?"
As if responding to his words, a bright light gradually emerged from the darkness. It flickered, taking shape, coalescing into a human form.
A refined-looking man appeared—his long black hair tied in a ponytail, with two long bangs framing his face. He walked toward Masatsuki Aozaki at a measured pace.
Stopping just a few meters away, he stood still and observed him in silence.
"The Eleventh Kenpachi, Masatsuki Aozaki. I didn't expect to see you here."
His voice was deep yet steady, carrying an undeniable weight.
"A hero of Soul Society... the disciple personally favored by Genryūsai-sama. Why have you come to the Muken?"
"Just for these sinners? They've committed heinous crimes, but Seireitei has already passed judgment on them."
"What you're doing now is a direct challenge to Seireitei's authority. Do you think Genryūsai-sama will approve?"
Masatsuki Aozaki listened to the questions but gave no response. Instead, the corner of his mouth curled into a smirk, filled with disdain.
This man's Zanpakutō had a unique ability—he could merge his own Reishi with external matter and manipulate whatever he fused with. For years, he had maintained a continuous Bankai state, never once releasing it.
Even now, confined in Muken, with his power greatly weakened by the seals preventing him from interfering with the outside world, he still retained the ability to observe Seireitei and stay informed about its affairs.
That he knew about Masatsuki was no surprise.
"This isn't something you need to concern yourself with, Sōya Azashiro," Masatsuki said with a cold chuckle.
"Tch. As expected, that troublesome woman."
Sōya Azashiro's voice was soft, carrying a trace of exasperation, but he showed no sign of surprise.
His Zanpakutō, Urozakuro, was infamous for causing trouble. It wouldn't be shocking if she had already revealed all his information to Masatsuki, while he himself knew next to nothing about his opponent.
A severe disadvantage.
Masatsuki's control over Reishi was far too unusual. Sōya couldn't observe him directly, only gathering information through others.
And intelligence gathered secondhand was never as reliable as seeing something for himself.
"Don't waste your energy. The stronger a person's Reiatsu, the more resistance they have to your ability, isn't that right?" Masatsuki's expression turned cold.
"Even here in Muken, where your abilities seem stronger than they are outside... the gap between our Reiatsu is far too vast."
"And that's not even considering the restrictions binding you now."
"Even if you were free, you'd never be able to invade my body."
Sōya Azashiro's face darkened slightly.
"Why not let that woman out to see me?"
"Oh? You want to see her?" Masatsuki sneered. "What's wrong? Even after all this time, the weak little brother still can't live without his big sister protecting him?"
He chuckled.
"But she's too damn noisy. Even now, she won't shut up."
"If I let her out, she'll just keep nagging endlessly."
"And I don't have that kind of time to waste."
Masatsuki's smirk widened, sharp and taunting.
"But I do hate men who keep coveting my body... always lurking, always watching from the shadows."
"So I think I'll take this opportunity to teach you a lesson."
"Maybe then, you'll finally understand what lines shouldn't be crossed."
"Consider it my way of giving her closure—fulfilling her wish."
Masatsuki grinned, baring a row of perfectly white teeth.
That smile, twisted and cruel, carried a chilling aura—like a demon baring its fangs.