A surge of purple spiritual pressure erupted as Wonderweiss transformed. His limbs elongated, his shoulders and hips broadened, his torso becoming hollow. The wound inflicted by Shunsui Kyōraku vanished, healed by his high-speed regeneration.
He roared, rising into the air, and a purple Cero gathered in his mouth, expanding into a powerful beam that shot towards Captain-Commander Yamamoto.
Yamamoto's spiritual pressure flared, and flames ignited on Ryūjin Jakka. However, the flames were instantly drawn into Wonderweiss, leaving only wisps of smoke on Yamamoto's blade.
"Hmph. Sōsuke Aizen, do you truly believe a mere flame-eating Hollow can defeat me? You underestimate me."
Despite Ryūjin Jakka's extinguished flames, Yamamoto remained unfazed. He ripped off his captain's haori, revealing his lean, muscled torso, a testament to decades of rigorous training. He raised his Zanpakutō, its now-dull blade meeting Wonderweiss's Cero.
BOOM!
The Cero split in two and exploded on either side of Yamamoto, two mushroom clouds rose from the devastated replica Karakura Town below.
Yamamoto vanished before reappearing before Wonderweiss.
"Bankai – Zanka no Tachi, East: Kyokujitsujin!"
The world seemed to lose its color. All moisture in the air evaporated. Yamamoto's blade, now resembling a scorched katana, devoid of its usual flames, radiated intense heat.
Even Wonderweiss, driven by instinct, recoiled in fear. But it was too late.
Yamamoto gently tapped Wonderweiss with his blade.
BOOM!
Wonderweiss's body disintegrated, starting from the point of contact. A massive fissure, hundreds of meters long, appeared in the ground behind him. Even his high-speed regeneration couldn't keep pace with the destructive power of Zanka no Tachi. His attempts to heal only delayed the inevitable. Once his spiritual pressure was depleted, he would cease to exist.
As Yamamoto turned to face Aizen, his expression shifted. Red lines, like veins of fire, appeared on Wonderweiss's crumbling form. Yamamoto recognized the familiar spiritual pressure. It was the absorbed flames of Ryūjin Jakka, sealed within Wonderweiss's body. Upon his death, they would be released, an explosion powerful enough to kill even Yamamoto at this range.
Without hesitation, Yamamoto activated his defense. "Zanka no Tachi, West: Zanjitsu Gokui!"
BOOM!
A second sun blazed in the sky, dwarfing the explosion of Wonderweiss's released flames, reducing them to mere wisps of black smoke.
Yamamoto stood wreathed in flames, radiating unbearable heat, like a miniature sun, which seemed to burn one's eyes blind if one looked directly at it.
His flames enveloped him in a 15 million-degree aura. Even Yamamoto couldn't maintain this state for long. The intense heat, comparable to the sun's core, would eventually consume everything, including himself.
"Sōsuke Aizen!"
Having dealt with Wonderweiss, Yamamoto turned his attention to his former subordinate. While his power remained at its peak, his aging body couldn't sustain his Bankai indefinitely. The strain was considerable. He had to end this quickly.
BOOM!
Forced to defend himself against the intense heat, Aizen unleashed his spiritual pressure to extinguish the flames within a small radius around him. Otherwise, he would be incinerated.
The two titans clashed. Yamamoto's heat was comparable to the sun's core, and threatened to consume Aizen.
Aizen, in turn, used his spiritual pressure to shield himself, a constant drain on his reserves. Without Ryūjin Jakka's ability to generate flames, Aizen's defense was far more taxing. He was losing spiritual pressure at an alarming rate.
However, with the Hōgyoku, he wasn't concerned. The Hōgyoku's true power was to manifest the desires of those around it. Having merged with Aizen, it responded to his will, amplifying his spiritual pressure, fueling his evolution.
"I've got you!"
Yamamoto sensed Aizen's spiritual pressure and opened his eyes. Zanjitsu Gokui's heat had transformed the replica Karakura Town into an inferno. Anyone within its range had to constantly expend spiritual pressure to shield themselves. Those with insufficient reserves were instantly incinerated. Aizen's attempts to defend himself had revealed his location.
Yamamoto planted his Zanpakutō in the ground. "Oh, fallen warriors, ashes of those consumed by my flames… I grant you the joy of battle once more! Rise and assist me in burying this enemy! Zanka no Tachi, South: Kaka Jūmanokushi Daisōjin!"
Flames erupted from Ryūjin Jakka. Countless skeletal warriors, formed from solidified flames, emerged, some armed, some not, charging towards Aizen.
"My, my. This is…" Aizen shook his head, raising his right hand. He began chanting a high-level Hadō, omitting the incantation. "Hadō #99. Goryūtenmetsu!"
BOOM!
The earth cracked, the replica Karakura Town began crumbling as if struck by a massive earthquake. Five blue dragons, each a hundred meters long, materialized, their combined power obliterated Yamamoto's fiery army. They then rushed towards Yamamoto.
Yamamoto, undeterred, charged to meet them. "Zanka no Tachi, North: Tenchi Kaijin!"
He swung his blade, and everything before him was incinerated, not even ash remaining. Even Aizen's Goryūtenmetsu was consumed by the flames.
Aizen himself was caught within the attack's range.
"Ahhh!"
He screamed as the flames consumed his lower body, threatening to engulf him completely. Only the Hōgyoku's power, fueling his regeneration, saved him.
"That bastard!" Yamamoto glared at the rapidly regenerating Aizen. Having used all four of Zanka no Tachi's abilities, he needed a moment to recover before resuming his attack.
"Ahhhh!"
Aizen roared, and his spiritual pressure surged again, enveloping him in a white cocoon, like a moth preparing to emerge.
BOOM!
The cocoon exploded, revealing Aizen's transformed form. His spiritual pressure now rivaled Yamamoto's Bankai.
"Thank you, Captain-Commander Yamamoto. Without your… assistance, my fusion with the Hōgyoku would have taken considerably longer." He flashed before Yamamoto. His spiritual pressure alone now matched Yamamoto's. "As a token of my gratitude, allow me to demonstrate my newfound power and defeat you completely."
BOOM!
A burst of flames interrupted him. Yamamoto stepped out of the inferno.
"Defeat me? Aizen, do you know who I am? I am Genryūsai Shigekuni Yamamoto, the strongest Shinigami in a thousand years!"
"Captain-Commander Yamamoto, aren't you overestimating yourself?"
Aizen sensed the Hōgyoku's continued connection to him had not weakened despite Gin's distance. He shifted his attention back to Yamamoto. He acknowledged Yamamoto's power. He had nearly been killed by Zanka no Tachi's combined assault. If not for the Hōgyoku, he would be dead. However, facing death, driven by fear, the Hōgyoku had responded, triggering his evolution. His power had increased dramatically. He now saw Yamamoto in a different light.
"Compared to Captain Ailin, you pose less of a threat. Are you truly the strongest Shinigami? Perhaps you were, once. But now… shouldn't that title be preceded by the word 'former'?"
"Hmph. Whether I'm the strongest is determined not by words, but by the blade in my hand!" Yamamoto roared, charging towards Aizen.
This time, Aizen didn't dodge. He unleashed his spiritual pressure, meeting Yamamoto's attack head-on.
CLANG!
BOOM!
The impact sent Aizen flying, his Zanpakutō knocked aside by the force of Ryūjin Jakka's heat. Aizen's body, scorched and wounded, began regenerating. Even with his enhanced power, the disparity in their Zanpakutō's abilities was evident.
However, his evolution had granted him increased resilience. While still at a disadvantage, Aizen could now endure Yamamoto's attacks. He wouldn't be easily defeated.
The two figures, one red, the other blue, clashed in the sky above the replica Karakura Town.