"Bankai!"
Bokukō, now in his tiger form, had lost all trace of his previous laziness. His deep voice mingled with a savage roar.
"Rin'en Bokukō!"
Viscous Spirit Ink surged out, churning violently through the cave.
Bubbles appeared one after another, only to burst just as quickly.
Myōki hadn't lied.
He really couldn't control Bokukō.
As a mirror of Muten Natsu's Soul, Bokukō possessed the same defining trait as Muten Natsu.
Laziness.
The materialized Bokukō everyone had been seeing was merely a projection of his true materialized form.
Bokukō's actual materialized form had been asleep the entire time within the ink stains he left behind.
His cat-like movements were essentially sleepwalking performed by the real Bokukō while he slept, and the sounds he made were nothing more than indistinct sleep-talking.
By absorbing Reishi, Myōki could provide simple guidance to the sleeping Bokukō's movements.
Only two situations could actually wake Bokukō.
The first was what had happened during the previous battle. When confronted with danger, Bokukō would awaken and release his power.
The second was more troublesome.
Only when Bokukō discovered a serious problem that directly concerned him, and no one else could solve it, would he willingly wake up and take action.
As long as someone else could handle the problem, the lazy Bokukō had absolutely no intention of moving.
That was also why Bokukō had left Muten Natsu.
He used Bankai far too often!
Problems that could clearly be solved without Bankai kept interrupting Bokukō's perfectly good sleep because Muten Natsu insisted on waking him up again and again.
That overwhelming urge to attack whenever Rin'en Bokukō burst out of the Spirit Ink was, in truth...
Just his bad temper after being woken up.
As for why Myōki had left Muten Natsu, there were mainly two reasons.
First, Myōki didn't trust Bokukō to go off on his own. He was worried Bokukō might cause too much destruction, so someone needed to keep an eye on him.
Second, this was the perfect opportunity.
A light screen appeared before Muten Natsu.
[As long as I create the illusion that I materialized too]
[even though I never actually materialized]
[I can still do absolutely nothing]
A complete success at slacking off.
"As expected of my Zanpakutō." Muten Natsu picked up his pace. "You were also planning to gather intelligence, right?"
[If thinking that makes you feel better]
[then sure]
Muten Natsu reached for the Asauchi at his waist.
"Bound by Convention, Myōki!"
The scabbard vanished and merged into Muten Natsu's body.
The blade changed from a curved outer edge to a subtle inward curve before disappearing into the palm of Muten Natsu's left hand.
"Myōki?" Rukia Kuchiki noticed the change in his Zanpakutō. "Myōki came back?"
Muten Natsu clicked his tongue. "He never left. He's been slacking off inside my body this whole time."
Rukia Kuchiki looked helpless.
"...As expected of your Zanpakutō."
[Muramasa's ability essentially severs the connection]
[between a Zanpakutō and the Shinigami's Soul]
[I have already restored the connection between you and Bokukō]
[You can subdue him at any time]
[But before that]
[use Heaven's Will to defend]
"Compass, Line, Square, and Ink."
The Hell Arm Armor appeared over Muten Natsu's left arm.
"Heaven's Will!"
Dense white clouds surged outward, completely enveloping Muten Natsu and Rukia Kuchiki.
The next instant, a violent tremor shook the cave.
A ferocious head burst from the Spirit Ink and lunged toward Muramasa and Aura Michibane, carrying an overwhelming fury at having been woken up.
Aura Michibane dispersed like mist and vanished without a trace.
Muramasa raised a hand and released a spreading sound wave.
As the Spirit Ink churned, Rin'en Bokukō's savage head froze in midair, its movements suppressed by the bizarre sound waves.
But there was nothing Rin'en Bokukō hated more than being restrained.
The enormous head trembled.
Ripples spread through the Spirit Ink, and a gigantic hand suddenly reached out, seized Muramasa, and squeezed.
Murky Reiatsu suddenly erupted.
Pitch-black matter oozed from between the fingers of the hand formed from Spirit Ink.
One Gillian after another squeezed out from the enormous hand, thick black smoke pouring from their bodies as the Spirit Ink corroded them.
More and more Menos emerged, gradually forcing Rin'en Bokukō's fingers apart and revealing the horribly distorted Muramasa within.
His thin body twisted and deformed.
Hollow masks appeared one after another across Muramasa's body, roaring as they tore themselves free and transformed into enormous Hollows.
Muramasa's body was gradually losing its original shape, becoming something like a tumor overgrown with mold.
Within Rin'en Bokukō's massive head, Bokukō voraciously devoured Rin'en Bokukō's power as bone-white armor gradually formed over his body.
Since a massive body couldn't inflict effective damage on Muramasa, he would compress that body, concentrate the power, and attack another way.
But before Bokukō could act, Genryūsai Shigekuni Yamamoto, who had remained still for so long, suddenly dispelled the barrier and appeared in front of Muramasa.
Several Menos roared and lunged at Genryūsai Shigekuni Yamamoto.
The elderly man gave a thunderous shout.
His terrifying Reiatsu alone forcibly drove them back.
Without even using his Zanpakutō, Genryūsai Shigekuni Yamamoto threw a punch and struck Muramasa amid the surrounding Menos.
Muramasa's distorted head shattered instantly.
Fragments of bone and flesh traced the vague outline of a fist through the air, smashing through the body of a Menos before burying themselves in the stone wall.
"Phew~"
Genryūsai Shigekuni Yamamoto let out a long breath. As though nothing had happened, he returned to looking like a slightly hunched old man.
"Well done, Myōki, Bokukō. With the opening you created, this old man..."
Before he could finish, the armor covering Bokukō disappeared.
Bokukō shrank back down to the size of a cat, gave Genryūsai Shigekuni Yamamoto an annoyed sideways glance, yawned, and flopped onto the ground.
A light screen floated above Bokukō's head.
[Looks like he failed to separate Ryūjin Jakka]
"Muramasa's power can be resisted by closing off one's heart, but by the time I realized what was happening, it was already too late. I could only seal myself away to prevent Ryūjin Jakka from losing control." Genryūsai Shigekuni Yamamoto glanced at the gradually dispersing Hollows. "As long as I don't draw my sword, I can delay..."
Click.
Genryūsai Shigekuni Yamamoto lowered his gaze to the Zanpakutō in his hand.
The simple, ancient-looking blade had slid several inches out of its sheath on its own.
WHOOSH!!!
Raging flames suddenly erupted, sweeping wildly across everything around them.
Genryūsai Shigekuni Yamamoto released his Reiatsu to suppress them, but could only watch as thin wisps of fire entered the surrounding Hollows.
"When a Zanpakutō materializes, it absorbs Reishi from the atmosphere to construct its body," Aura Michibane's voice echoed through the cave. "During that process, even the strongest Zanpakutō can be controlled through manipulation of Reishi. All you need to do is inject the Reishi meant for its materialized body into another spiritual body..."
One Hollow after another began collapsing inward as though something were dragging them toward the center.
Muramasa, who had already been killed, appeared once more before Genryūsai Shigekuni Yamamoto.
His charred body was covered in glowing crimson cracks, and something resembling molten magma could faintly be seen flowing beneath them.
"So this is the power of Ryūjin Jakka?"
Muramasa raised a hand.
His burning index finger pierced his own temple and slowly stirred inside.
"Found it..."
His expression twisted.
"His location, inside your memories."