The echoes of battle had long faded, but the weight of the war still lingered in the air.
Aizen, Natoro, Raizen, and their remaining forces had retreated from the battlefield. Las Noches, once a symbol of their dominion over Hueco Mundo, was now a shattered ruin. The Espada had fallen, the Hōgyoku had reshaped reality itself, and Ichigo Kurosaki had surpassed them all—if only for a moment.
But Aizen had never considered that battle a true defeat. Merely a necessary sacrifice.
Now, deep within the furthest recesses of Hueco Mundo, where no soul—Shinigami, Hollow, or Quincy—had ever dared to tread, the real game was beginning.
The Gathering in the Abyss
Beneath the remains of Las Noches lay an ancient, hidden chamber—a place untouched by time. Massive, jagged pillars of obsidian-like stone jutted from the ground, forming a throne-like structure in the center. The air was thick with an overwhelming spiritual pressure, so dense that even lesser Arrancar would be crushed beneath its weight.
Here, Aizen, Natoro, Raizen, Gin, Tōsen, and Kirio stood together once more.
Gin was the first to break the silence, his ever-present smirk barely masking his curiosity. "So, Aizen-taichō… What's the next step? Can't imagine ya dragged us down here just for a reunion."
Aizen's eyes gleamed with an unnatural luminescence, the remnants of his fusion with the Hōgyoku still altering his very being. "The battle with Ichigo was… informative. But it was merely the prelude to something far greater."
Natoro scoffed. "You're telling me we're still playing the long game? We should be striking now, reclaiming what's ours."
Aizen turned to him, smiling slightly. "Impatience does not suit you, Natoro."
Raizen, standing beside his father, crossed his arms. "Then what are we waiting for?"
Aizen's voice carried an eerie certainty. "The Soul King."
A hush fell over the room.
Even Natoro, as power-hungry as he was, felt a flicker of hesitation at the mention of that name.
Kirio Hikifune, the former Zero Division captain who had defected to Aizen's side, narrowed her eyes. "You're not serious."
Aizen turned to her, his smile never faltering. "Why would I not be?"
Kirio's fingers twitched, as if gripping the hilt of a blade that wasn't there. "The Soul King is beyond us. Even with everything we've gained, we are still only standing in his shadow. He is the foundation of existence itself."
Aizen chuckled. "And yet, he remains bound, imprisoned within his own throne. Tell me, Kirio, do you truly believe the world operates as it should?"
Kirio hesitated. She had been a member of the Royal Guard, had seen things that no mere captain could even begin to comprehend. She knew the truth. The Soul King was not a god—not in the way the Soul Society claimed. He was a prisoner, a puppet, a linchpin forced into place to maintain a broken system.
She exhaled slowly. "You want to kill him."
Aizen's smile widened. "Not kill. Replace."
Natoro's eyes darkened with intrigue. "Now that… is a throne worth taking."
The Plan: Ascension to the Soul Palace
Aizen moved to the center of the chamber, raising his hand. The Hōgyoku pulsed, and the space around them twisted, revealing a hidden gateway—one even the Soul Society had long forgotten.
"A direct path," Aizen explained, "to the Royal Realm."
Gin raised an eyebrow. "Ya mean the one Urahara built? Thought that got sealed off after our little invasion."
Aizen shook his head. "There was more than one way in."
Raizen smirked. "And here I thought breaking into heaven would be difficult."
Aizen's expression remained serene. "It will be."
Kirio folded her arms. "Zero Division won't just let us waltz in."
Aizen's gaze sharpened. "They will have no choice."
Natoro cracked his knuckles, a grin forming on his lips. "I've been waiting for a real fight."
Aizen turned his back to them, looking toward the swirling darkness of the gateway. "Then prepare yourselves. The next phase of our conquest begins now."
The Rebellion Within Soul Society
Meanwhile, back in Soul Society, the aftermath of Aizen's escape and defection had left the Gotei 13 in disarray.
Yamamoto, still recovering from his battle, had begun rebuilding the ranks of the Captains, but the scars of betrayal ran deep. The Soul Reapers knew that Aizen would return. They just didn't know when or how.
But what they didn't realize was that their own ranks were beginning to fracture.
Deep within the First Division Barracks, a secret meeting was taking place.
Urahara Kisuke sat across from Shunsui Kyōraku, Jūshirō Ukitake, Soi Fon, and Mayuri Kurotsuchi.
"The Soul King is in danger," Kisuke stated plainly.
Shunsui let out a long sigh. "Tell me something I don't know."
Urahara's expression darkened. "It's worse than you think. Aizen has found a way in."
Silence filled the room.
Soi Fon clenched her fists. "If Aizen reaches the Royal Realm…"
Mayuri's grin widened. "Then we get to see what happens when a god dies."
Jūshirō Ukitake shook his head. "This isn't a joke, Kurotsuchi."
Mayuri chuckled. "I know. That's what makes it so exciting."
Shunsui adjusted his hat. "Then it looks like we don't have much time."
Urahara nodded. "No. We don't."
The Invasion Begins
Back in Hueco Mundo, the moment had come.
The gateway to the Royal Realm flared to life.
Aizen stepped forward, his reiatsu suffocating the air.
Behind him, Natoro, Raizen, Kirio, Gin, and Tōsen followed, their power radiating like dark suns.
Raizen glanced at his father. "This is it, huh?"
Natoro grinned. "A new age begins today."
Aizen took one final step forward, into the abyss.
The world began to shatter.
In the deepest chamber of the Royal Palace, a single eye opened.
It had not moved in thousands of years.
And yet, as it gazed upon the approaching threat, a whisper echoed through the void.
"The usurpers… have come." The Fall of the Royal Guard
Aizen, Natoro, Raizen, Kirio, Gin, and Tōsen emerged from the swirling darkness into the Royal Realm—the sacred home of the Soul King and his Zero Division.
The moment their feet touched the floating city of Tenchūren, an overwhelming force of reiatsu crashed down on them.
"So, you finally arrived."
Atop the grand staircase leading to the Soul King's Palace, five figures stood tall—the legendary Zero Division.
Ichibē Hyōsube, the Monk Who Calls the Real Name.
Ōetsu Nimaiya, the creator of the Zanpakutō.
Tenjirō Kirinji, the hot spring demon.
Senjumaru Shutara, the weaver of fate.
And last, but not least, a man Kirio once called an ally—Senjumaru's twin brother, Yakurō Shutara, a warrior of unmatched tactical brilliance.
The Zero Division had been waiting.
Aizen smiled. "As expected. You all have done well to preserve this fragile order."
Ichibē took a step forward, his voice booming. "You dare set foot here, Sosuke Aizen, bearer of the Hōgyoku, and your wretched followers?" His eyes locked onto Kirio. "And you, Kirio Hikifune… A traitor to the Soul King."
Kirio's face remained unreadable. "I walk the only path worth taking."
Ichibē's grin widened. "Then let's see if you can walk at all after this."
With a single swipe of his brush, the battlefield was set ablaze with spiritual pressure. The war for the heavens had begun.
Raizen's First True Test
Raizen stood his ground as Ōetsu Nimaiya dashed toward him in a flash of light-speed movement.
"Let's see if you can handle a real blade, kid," Ōetsu said with a smirk, summoning a pure Zanpakutō forged from the very essence of the Soul King's power.
Raizen's eyes narrowed. "Let's see if you can handle me."
With a single swing of his Shikai, 'Seikatsu Kuro' (Black Life), Raizen unleashed a devastating wave of black energy, sending tremors across the floating palace.
Ōetsu dodged effortlessly. "Tch. You're fast, but not fast enough."
In an instant, Ōetsu appeared behind Raizen, blade at his throat.
But Raizen grinned.
"Wrong move."
With an explosion of pure darkness, Raizen's Bankai activated.
Natoro vs. Ichibē: The Fight of Names
As Raizen fought, Natoro found himself face-to-face with Ichibē Hyōsube.
The Monk of Names held his gigantic ink brush, his eyes glowing with the power of the True Names of all things.
"You wish for the throne, but you don't even understand its name," Ichibē said, his voice booming like thunder. "You are nothing but a greedy child reaching for the sun."
Natoro smirked. "Then let me show you how far a child can reach."
With a single motion, Natoro unleashed his Shikai, 'Yami no Kaen' (Flame of Darkness). Black fire erupted from his blade, consuming the very air itself. The flames licked at Ichibē's robes, but the monk merely chuckled.
"Your flames burn bright," Ichibē admitted. "But I don't need to kill you. I just need to erase your name."
Ichibē swung his brush, striking Natoro across the chest.
Instantly, Natoro felt something change. His spiritual pressure—his very presence—began to vanish.
Ichibē grinned. "With this strike, your power has been cut in half."
Natoro's eyes blazed with fury. "You think that matters?"
Ichibē tilted his head. "Oh?"
Natoro's reiatsu flared, overwhelming even Ichibē's spiritual pressure. The Hōgyoku within Aizen reacted to it.
And in that moment—Natoro evolved.
"Bankai," he whispered.
The black flames surrounding his blade intensified, turning into a swirling storm of infernal destruction.
'Yami no Kaen: Jigoku no Ten'nō' (Flame of Darkness: Hell's Emperor).
The moment he activated it, the very sky above them turned black.
Ichibē's smile finally faltered.
"Impossible…"
Natoro vanished from sight—then reappeared behind Ichibē.
One strike.
One explosion of dark fire.
And Ichibē, the great Monk Who Calls the Real Name, was sent crashing through the very foundations of the Soul King's Palace.
Aizen's Next Move
As his allies waged war against the Royal Guard, Aizen watched from above, eyes locked onto the highest throne.
The Soul King was waiting.
Aizen took a single step forward.
"Your reign is over."
And as he walked, the very fabric of reality itself began to shatter.
Far above, in the heart of the Soul King's Chamber, a new presence stirred.
A whisper echoed through the void.
"You have come far… but are you ready?"
Aizen paused.
And then, for the first time in centuries—he smiled.
To be continued…