Muramasa said, "Thank you, Shinigamis, and you, human."
"What's going on? Were you just using us to confuse the Shinigami? So you manipulated us for your own gain?" Katen demanded.
"I said so, is there a problem?" Muramasa showed a look of disdain.
"There's a huge problem. Now that everything's clear, we won't obey you anymore." Katen and Kyokotsu summoned their blades.
"Sorry, I have to go first. I don't have time to get entangled with you."
Flames erupted beneath Muramasa's feet, and a pillar of fire shot into the sky, piercing through the cave and forming a giant circular flame barrier that enveloped everyone. He then vanished.
"These flames are..."
"Ryujin Jakka!"
This was the first time Shin had seen Yamamoto's Ryujin Jakka, and it was indeed powerful.
Jūshirō looked at Yamamoto. "Sensei, what exactly is Muramasa?"
"Muramasa is a Zanpakuto, capable of invading the inside of a target's Zanpakuto, and can manipulate others at will, anytime, anywhere. Stopping his true objective is the top priority of the Gotei 13."
Yamamoto slowly revealed Muramasa's origins.
"Sensei, what is Muramasa's objective? Why did he invade your spiritual world?"
"His destination is the Reishi-dense area in the Human World, Karakura Town. What Muramasa seeks is in Karakura Town."
"What?" Shin exclaimed.
"Muramasa wants to break Koga's seal. He wants to bring Koga, his master, back into the world."
"Many years ago, Koga suddenly rebelled, throwing Soul Society into chaos. At that time, we paid a huge price to seal him away."
Jūshirō then asked, "So Muramasa invaded your spiritual world to find out how to break the seal?"
"Exactly."
"Once they join forces, Karakura Town could very well face total annihilation."
Shin was speechless. Karakura Town really was prone to disasters.
"We need to get out of here quickly."
Jūshirō tried to escape the encirclement from above, but the flames seemed to have a will of their own, following him like a shadow. He had no choice but to give up and return to his original position.
"I'll try."
Shin enveloped his entire body in crimson flames, summoned Wings of Crimson, and flew straight out. Ryujin Jakka's flame attacks couldn't harm him in the slightest.
"Old man, take your time subduing your Zanpakuto. I'll go deal with Muramasa."
Without Yamamoto controlling it, Ryujin Jakka was probably more than just a little weaker.
After escaping the predicament, Shin returned to Seireitei and informed Unohana of what had happened.
Then, he used the Kuchiki clan's Senkaimon to return to the Human World, accompanied by Rukia and Byakuya.
Muramasa had not concealed his Reiatsu, so they quickly found him. He was on an island in the middle of a lake, seemingly preparing to break the seal.
Seeing the group approach to stop him, Muramasa's eyes shed tears of blood, and he summoned countless Hollows.
"They're yours."
A samurai wearing a fierce mask and a cherry blossom petal ornament on his head slowly walked out, holding his sword towards everyone.
It was Byakuya's Zanpakuto—Senbonzakura.
Byakuya confronted Senbonzakura, while Shin and Rukia were surrounded by Hollows.
Muramasa stood before a giant tree, chanting an incantation.
"Grant purification to the black soul, clouds gather at the feet of the Most High, blood and covenant, the altar above... The time has come, open, lost coffin."
The barrier shattered, the giant tree vanished, and a massive coffin appeared, with several golden swords embedded in it.
Muramasa's eyes glowed purple, and the coffin changed in sync. The chains on it broke, the swords fell to the ground, and then a tall, gaunt, short-haired man emerged from within.
"Master!"
Hado #33: Sokatsui!
Rukia unleashed a Kido attack on Muramasa.
Muramasa casually deflected the fireball with his sword.
Looking at Shin behind Rukia, Muramasa couldn't help but be curious. "How did you break through Ryujin Jakka's encirclement so quickly?"
"Who knows?"
"Hahahahaha!" Muramasa burst out laughing.
"But you're a step too late. My long-cherished wish has finally been fulfilled."
'No, I came at just the right time. Just to take care of you all at once.' Shin thought.
Koga opened his eyes, and a massive purple Reiatsu erupted. Even after being sealed for hundreds of years, his power was still formidable.
Muramasa excitedly walked forward. "I've waited a long time for this moment. Now, let us fulfill that grand ambition, Koga."
But Koga raised his half-broken Zanpakuto and stabbed Muramasa in the stomach.
"Wh-why?"
"When I was about to be sealed, I called out to you, but you didn't appear. From that moment on, you were useless to me."
"You're just a Zanpakuto, you only need to act according to my will." Koga kicked Muramasa away.
Muramasa asked in pain, "Are... aren't we comrades?"
"Comrades? To me, you're just a sword. A mere tool for killing."
Saying that, Koga swung his sword at Muramasa again.
Clang!
A sword blocked the attack, it was Byakuya, with Senbonzakura standing by his side.
"How can this be? Senbonzakura was subdued so quickly?" Muramasa was somewhat incredulous.
"I subdued Senbonzakura from the beginning and had him lie in wait beside you. If I couldn't stop you, then I would deal with this man myself." Byakuya looked at Koga.
Koga, seeing Byakuya's familiar attire, already knew that Byakuya was also from the Kuchiki clan.
Byakuya slowly recounted Koga's history—
Kuchiki Koga was a genius Shinigami centuries ago, and also the son-in-law of the Kuchiki clan.
Byakuya's grandfather, Ginrei, was very worried about Muramasa's abilities and repeatedly warned Koga not to rely too much on the power of his Zanpakuto.
Later, Koga was framed and imprisoned in a factional struggle, but Ginrei still didn't give up on him, racking his brains to find a way to save him.
However, Koga lost control, killed Soul Reapers, was consumed by hatred, and attempted to overthrow Soul Society, ultimately being sealed by Yamamoto and Ginrei together.
"The 28th head of the Kuchiki clan—Kuchiki Byakuya, today cleanses the clan."
"You bastard! As expected of the Kuchiki clan, all of you are arrogant and boastful!"
Muramasa, clutching his wound, stood up. "Koga, let me lend you a hand."
Koga, however, raised his Zanpakuto, broke it, and threw it in front of Muramasa.
"I told you, you're just a troublesome waste now. I don't need an unstable sword like you, I'm enough on my own."
Muramasa knelt on the ground, his expression desolate.
The next moment, black Reiatsu erupted from Muramasa, engulfing him. His body continuously expanded, and countless Menos Grande appeared around him.
Shin shook his head.
Muramasa was pathetic but he wouldn't show sympathy to an enemy.
"Captain Kuchiki, Koga is yours. I'll deal with Muramasa."
"Alright."
Koga engaged Byakuya in battle with the halberd from his coffin.
Just as Shin was about to make his move, a sudden change occurred.
All the Menos Grande were absorbed by Muramasa, his Reiatsu dissipated, and Muramasa was completely transformed.
"Hollowfication? Arrancar?" Shin couldn't quite figure out what this thing was.
"A Zanpakuto and its master are one in body and soul, coexisting through soul fusion. Perhaps Muramasa devoured Hollows to maintain his physical form, replacing his Shinigami master." Rukia voiced her conjecture.
"No matter what it is, just kill it."
Shin flew towards Muramasa.
Great Blade of Crimson!
Muramasa blocked with his hand, but half of his body was directly sliced off. The next second, Muramasa's two halves slowly reconnected.
'Can he recover so quickly even under the effect of the Great Blade of Crimson? This guy is probably equivalent to a Resurrección Arrancar.'
A massive black Reiatsu erupted from Muramasa, enveloping him and Shin, forming a spherical object.
A giant Garganta tore open in the sky, and countless Hollows surged out from within.
Rukia watched Shin being pulled into the sphere, wanting to help, but found herself struggling to deal with one Hollow after another. Without Sode no Shirayuki, she had to constantly unleash Kido to cope.
Just as she was about to give up—
"Rukia!"
"Renji!"
She turned around to see Renji, along with numerous captains and lieutenants.
Outside the sphere, a fierce battle raged, but inside, it was calm and peaceful.
Shin found himself in a new space. It was an endless, tranquil lake, with countless stone pillars standing upon it.
At this moment, Muramasa, in his normal state, walked across the water.
Shin asked, "Where is this?"
"This is Koga's spiritual world. I don't know why I'm here either."
Muramasa shook his head. "I have a question."
"Why didn't you stop me from breaking Koga's seal? Since Senbonzakura was subdued early on, those Hollows shouldn't have been able to stop you."
Shin asked, "You found out. What if I said I knew your objective from the start and had no intention of stopping you? Do you believe me?"
Muramasa was shocked. "How could that be?! Did you deliberately let me unseal Koga?"
Shin nodded. "You got it right. That guy was sealed in Karakura Town like a ticking time bomb, he had to be dealt with."
Actually, if Koga hadn't been completely consumed by hatred and was uncontrollable, taking him under his wing might not have been out of the question.
"Impossible! Just a mere human!"
Muramasa disbelieved that Shin could have known his plans and used him. His and Koga's story was sealed away by Soul Society, and even among Shinigami, very few knew about it. And Byakuya would never tell a human about the clan's disgrace.
"Ahhh!"
He roared and charged at Shin with his sword.
Shin exchanged a few blows with him, then unleashed a fiery slash to force him back.
Muramasa raised his right hand, pointing it at Shin. Shin felt as if his body was bound by ropes, unable to move.
Looking down, in the reflection on the lake, he saw that countless hands were tightly entangled around him. So, he manipulated his crimson flames to attack Muramasa's reflection.
Bang!
A huge splash erupted from the water, and Shin successfully broke free.
Muramasa was stunned again. "Why are you so clear about my techniques?"
"Hehe." Shin smiled but didn't explain.
Seeing him remain silent, Muramasa charged forward again.
Shin stabbed Muramasa, but he disappeared.
"From the moment we clashed, you were already under my spell."
Countless Muramasas appeared in the sky, his voice echoing through the space.
"Illusion? Too bad."
Judgment!
A giant eye of flame appeared above Shin's head.
Shin pinpointed Muramasa's true body and sliced him away with a single strike.
Muramasa crashed into a stone pillar. Just as he was about to get up, a sharp pain shot through his chest.
A large hole appeared in his chest, then vanished, only to reappear, repeating endlessly, causing him excruciating pain.
Seeing this, Shin knew Muramasa was beyond saving. He had devoured too many Hollows over the years, and now the grudges of these Hollows would turn around and consume him.
At this moment, the sky began to shatter, and the stone pillars started to collapse. This spiritual world was on the verge of collapsing.
"Let me put you out of your misery."
Shin took a deep breath, activated his crimson flames, and wielded his blazing sword.
Eleventh Form: Dragon Sun Halo Head Dance!
A giant fire dragon roared and devoured the wailing Muramasa.
—
Outside the sphere.
Byakuya ended Koga with "Shūkei: Hakuteiken".
The rest of the group concentrated all their power to close the gigantic Garganta.
Everyone was waiting for Shin, not daring to rashly destroy the sphere for fear of accidentally harming him.
Suddenly, the sphere erupted with an intense light, forcing everyone to close their eyes. Moments later, the light vanished, and the sphere shattered.
Muramasa transformed into a broken Zanpakuto and slowly dissipated.
"Nohara!" Soi Fon rushed forward.
"Don't worry, I'm fine."
Seeing Shin completely unharmed, everyone breathed a sigh of relief.
"Oh! Right, Rukia, this is your Zanpakuto. Sorry about that."
Shin took out the broken Sode no Shirayuki from his Yogasa and returned it to Rukia.