After things unfolded like in the original story in Central 46—
"To all Captains and Lieutenants of the Gotei 13, and to the Ryoka, I am Lieutenant Kotetsu Isane of the Fourth Division. What I am about to say is absolutely true..."
At this moment, all Captains, Lieutenants, and the group of Shin within the Seireitei heard Isane's message.
"How is that possible?"
"Captain Aizen isn't dead?"
"Captain... he's a traitor?"
Everyone was shocked by Aizen's century-long scheme, and even more enraged by his casual manipulation of others' fates.
Renji finally understood how terrifying the person before him was. But he would never stand by and watch Rukia be taken away.
"Abarai, as my former subordinate, you'd best not be too stubborn. You know, it's very difficult to gauge the force needed to step on an ant without crushing it." Aizen advised lightly, but his words were full of extreme arrogance.
Renji was about to fight to the death, but a hand rested on his shoulder.
"Step back. I'll handle him."
Renji looked at Shin, he only knew of this person but hadn't formally met him. But their goals were the same, so he retreated with Rukia.
Aizen didn't care. In his eyes, the Hōgyoku was already his for the taking.
"Yo! Captain Aizen, you faked your death and framed me. I can't just pretend nothing happened."
Although Shin didn't want to stop Aizen from getting the Hōgyoku, he held grudges. Aizen had tricked him, so he had to collect some interest first.
"Nohara-san, holding grudges is not a quality a strong person should possess." Aizen displayed his signature gentle smile.
"I don't consider myself strong."
"No, Nohara-san, you are different from these ants. Your power is extraordinary. In time, you will surely transcend the Shinigami."
"No need for more words, let's fight. We didn't get to fight to our heart's content last time."
[Triggered Mission: Defeat Aizen Sosuke]
[Shatter Aizen's arrogance and grind him into the dirt]
[Reward: 4000 Points]
This mission... it'd be good enough to just win, but I have to grind him into the dirt?
"Since that's the case, then allow me to show you my power."
Aizen wanted to see Shin's true strength.
As soon as he finished speaking, an extremely powerful Reiatsu erupted from him. The oppressive feeling caused those with low Reiatsu present, such as Orihime, to all fall to the ground.
Yoruichi and the others quickly led them to retreat.
Mayuri watched this scene with eager eyes. Now he could properly observe Shin's power.
Great Blade of Crimson!
Shin attacked first, this time holding nothing back, the speed and destructive power of his flame katana reached their peak.
Boom!
Accompanied by a violent explosion, a large crater was blasted into the ground but Aizen had already appeared behind Shin.
Bakudō #61. Rikujōkōrō!
Six light fragments instantly sealed Shin.
Hadō #88: Hiryū Gekizoku Shinten Raihō!
A massive lightning-attribute shockwave was unleashed from Aizen's hand.
Boom!
A pale blue light cannon enveloped Shin, and the resulting explosion generated a wave of air that stirred up a sky full of dust.
When the dust and smoke cleared, a man of fire was revealed.
Shin had covered his entire body with flames, forming a fiery battle suit. This was a technique he developed by referencing Yamamoto's Zanka No Tachi West Zanjutsu Gokui, combining offense and defense.
"Aizen!"
With an angry roar, a colossal figure descended from the sky.
Sajin slashed at Aizen, kicking up dust, but Aizen caught his blade with his bare hand.
"It's been a long time since I've seen you like this, but interrupting someone else's battle isn't a good habit." Aizen smiled.
Hadō #90. Kurohitsugi!
A black, square coffin with a cross embedded in it enveloped Sajin. Then the coffin disappeared, and Sajin fell into a pool of blood.
"As expected of Captain Aizen. To be able to cast even Kido #90 without incantation. When did you learn that?" Gin praised.
"No, it failed. I couldn't even unleash a third of its original destructive power." Aizen's tone was calm.
Shin was a bit speechless. He had already confronted Aizen, yet this big dog still ran out to give away a kill.
Everyone watching from a distance was shocked by Aizen's displayed strength. Both were Captain-level, yet Aizen had instantly defeated Sajin.
"The annoying bug has been dealt with. Nohara-san, let's continue."
Thirteenth Form!
Shin used the final form of Sun Breathing for the first time, performing Forms One through Twelve in a complete, continuous cycle. Everywhere he passed turned into scorched earth.
Aizen continuously blocked with his Zanpakuto, but the overflowing flames ignited his sleeve and spread relentlessly, like a maggot clinging to bone. Aizen tore off his sleeve, revealing burn marks on his arm.
"Is this the power of the sun? It is very overbearing." Aizen praised.
Shin manipulated the flames, turning them into a torrent of fire that swept towards Aizen.
Whoosh... Whoosh...
Aizen continuously dodged with Shunpo.
Suddenly, a pillar of lava erupted from underground, spraying towards Aizen at an extremely high speed.
It turned out that Shin had melted the earth with his flames, launching a surprise attack from below while Aizen was busy dodging frontal assaults.
Bakudō #81: Dankū!
A glass-like defensive wall unfolded beneath Aizen.
Bang!
The lava pillar pierced through the defensive wall.
Aizen was slightly startled. His shoulder had been pierced, leaving a finger-thick wound.
"It's not over yet."
A giant fiery hand clenched towards Aizen.
Hadō #63: Raikoho!
Boom!
Golden lightning collided with crimson flames, resulting in a violent explosion.
Shin, holding Nietono no Shana, slashed towards the center of the explosion, but hit nothing.
Aizen had already used Shunpo to move behind Shin. His immense Reiatsu enveloped his blade, penetrating Shin's fiery battle suit and leaving a deep slash on his back.
In this close-quarters combat, speed was Shin's disadvantage. His Wings of Crimson were more suited for long-distance flight.
And Aizen was a typical hexagonal warrior, excelling in all aspects of Zanjutsu, Hoho, Bakudo, and Kido.
"It's been a long time since anyone has been able to injure me. Your power astounds me, Nohara-san."
Even though Aizen was injured, he still maintained a calm and composed demeanor.
"What a coincidence. This is the first time I've been injured as well."
Shin felt the pain from his back, which made him clearly realize the reality of this world.
Getting cut means you can die!
Since his transmigration, he had swept through everything. Coupled with his foreknowledge of the plot, although he verbally said he didn't think he was very strong, he inevitably became a bit arrogant psychologically.
Now, Aizen's slash was a timely reminder that while he was strong, he was still far from the very top.
Aizen said, "That truly is an honor. With such power, Nohara-san, why not do something meaningful? Why be subservient to others?"
Shin said indifferently, "What is meaningful? Sorry, I only want to do what I find interesting. As for being subservient to others? Heh. No one can order me around."
Aizen now felt more and more that Shin was a kindred spirit, only he hadn't yet grasped the truth of this world.
Shin turned to Yoruichi and the others in the distance and said, "Yoruichi, Soi Fon, take them away from Sōkyoku Hill. If you stay here, I can't guarantee you won't be caught in the crossfire."
"And take this big dog too."
Yoruichi gave Shin a deep look, knowing he was about to go all out. "Shin, be careful yourself."
Shin smiled confidently. "Don't worry, I know my limits."
"Gin, Kaname, you two retreat for now as well." Aizen gave them a look.
Gin now fully recognized Shin's strength. He was several times more powerful than when they fought before.
Collaborating with Shin might indeed be a good option.
He just didn't understand why he wasn't stopping Aizen from getting the Hōgyoku. Shin had told him earlier that he didn't intend to stop Aizen.
"Now, it's just us. Take this, Aizen!"
Tenpa Jōsai!
The earth was instantly ignited, and the entire Sōkyoku Hill turned into a sea of fire. Under the scorching of the flames, rocks melted and trees turned to ash.
The once towering Sōkyoku Hill was lowered by several meters, and hot magma flowed towards Seireitei, looking like a waterfall of fire from afar.
The Shinigami within Seireitei watched this scene, their faces filled with horror. Even from a great distance, they could feel the scorching heat.
The arriving Captains and Vice-Captains quickly used their abilities to stop the magma from spreading.
"Roar—"
A colossal roar echoed over Seireitei, as a monster tens of meters tall descended.
The monster had horns on its head, a pair of giant fiery wings on its back, and its body was covered in lava. It spewed flames capable of incinerating everything from its mouth, charging at Aizen.
Hadō #99. Goryūtenmetsu!
Five giant purple-black dragons formed from Reiatsu met it head-on.
Rumble!!!
Pillars of flame shot into the sky, and the shockwave from the violent explosion destroyed many buildings, turning it into ruins.
—
In Silbern.
A man in a deep red cloak sat on a throne.
"A human?"