"My, my. What a spectacular duel. I wonder who will emerge victorious, Captain-Commander Yamamoto or Sōsuke Aizen?"
Ailin stood in a corner of the replica Karakura Town, enveloped in a golden aura. Thousands of Zanpakutō, radiating golden light, hovered around him, shielding Shunsui Kyōraku, Jūshirō Ukitake, Soi Fon, and the other Shinigami from the intense heat of Ryūjin Jakka.
Kyōraku, wrapped in white bandages, sighed as he sensed the two powerful spiritual pressures clashing above. "This is… troublesome."
As Captain-Commander of the Gotei 13, Genryūsai Shigekuni Yamamoto was, without a doubt, considered the strongest Shinigami by his subordinates. Even Ailin, whose power rivaled Yamamoto's, couldn't displace him from that position in their minds. Yamamoto was seen as invincible.
From the current state of the battle, Yamamoto held the clear advantage. Each of his attacks inflicted grievous injuries upon Aizen. Any other Shinigami or Hollow would have been incapacitated, if not killed outright.
Aizen, however, regenerated almost instantly, his high-speed regeneration fueled by the Hōgyoku. And instead of weakening him, the constant injuries seemed to be pushing him further and his spiritual pressure was steadily rising.
"Captain Ailin, are you certain you won't intervene?" Kyōraku asked, turning to the golden figure.
When the Shinigami heard his question, they all pricked up their ears silently, wanting to hear what Captain Ailin had to say.
With the battle reaching such a critical point, even Captain-Commander Yamamoto had joined the fray. Only Ailin remained on the sidelines. Aside from his brief clash with Kisuke Urahara and his allies, he hadn't engaged any of Aizen's forces.
"Captain Kyōraku, you sensed Captain Urahara and the others' attack on me, didn't you? I doubt they would have acted without the Captain-Commander's approval. And if Captain-Commander Yamamoto doesn't want me to interfere, I see no reason to disobey."
The other Shinigami were startled. Urahara's attack had been sanctioned by Yamamoto? They exchanged uneasy glances. Ailin was right. Whether he intended to participate or not, Urahara's attack had effectively removed him from the battle. He might even resign from his captaincy after this.
"Well, I suppose you're right." Kyōraku, unsure how to respond, didn't comment on Yamamoto's decision. He understood the reasoning.
Ailin, especially after Rukia Kuchiki's dismantling of the Central 46 and the noble families' power structure, was an unpredictable element. While Yamamoto could control him under normal circumstances, during a battle like this, Ailin's allegiance was uncertain. Having Urahara restrain him had been a necessary precaution.
No one had anticipated Urahara abandoning his attack, however. Nor had they foreseen the extent of Aizen's power after merging with the Hōgyoku.
Now, their only hope was Yamamoto.
Kyōraku himself, if he released his Bankai, could likely challenge Aizen. However, as Yamamoto's current struggle demonstrated, Aizen's near-limitless spiritual pressure and regeneration made him a formidable opponent. He could afford to make mistakes. They couldn't. One wrong move, and they would be dead.
…
"So, this is Captain Tōsen's Bankai…"
Hitsugaya Toshiro felt he was plunged into darkness. When his vision, hearing and spiritual sense were all useless, he knew that he was enveloped by Captain Tosen's Bankai.
After Aizen's betrayal, the abilities of his Zanpakutō, along with Gin's and Tōsen's, had been revealed to the Gotei 13. Everyone participating in this battle knew what to expect. And Tōsen's Bankai, in many ways, was one of the most potent among the captains.
However…
Clang! Clang! Clang!
Within the darkness, Tōsen attacked, his limbs flailing. But each blow was met by Hitsugaya's blade, parried with surprising accuracy.
"Impossible!" Tōsen was stunned. Since mastering his Bankai, he had never failed. Even Love Aikawa, Rōjūrō Ōtoribashi, and Kensei Muguruma, over a century ago, had fallen to a single attack within its confines. How could Hitsugaya, a mere boy, counter it?
"Captain Tōsen, are you surprised I can defend myself within your Bankai?" Hitsugaya's voice echoed through the darkness. He turned, facing Tōsen, his movements precise, as if he could see.
"Impossible! You can see me?" Tōsen shouted.
Hitsugaya ignored him, continuing his explanation. "Captain Tōsen, any other captain trapped within your Bankai would likely be defeated. But you're facing me. My Zanpakutō, Hyōrinmaru, is the strongest ice-type Zanpakutō. It allows me to control the moisture within a certain radius. Master Ailin trained me to fight blind, relying solely on Hyōrinmaru's control over water to sense my surroundings."
He paused, then added, "As long as there's moisture in the air, your Bankai has little effect on me."
This last statement was a lie. Hyōrinmaru's power stemmed from its ability to condense moisture into ice. To sense his surroundings, Hitsugaya had to refrain from using that ability. Otherwise, he would deplete the very moisture he needed to "see." He hoped to deceive Tōsen into deactivating his Bankai to conserve spiritual pressure.
His words seemed to have the desired effect. Tōsen hesitated. But before he could deactivate his Bankai—
BOOM!
BOOM! BOOM! BOOM!
Explosions reverberated through the barrier, cracks appearedon its surface. The barrier stabilized, but the temperature within began to rise rapidly. The ice on Hitsugaya's dragon claw and wings began to melt.
Hitsugaya's expression shifted. "Is that… Captain-Commander Yamamoto's Bankai?"
Both he and Tōsen realized what was happening. The battle between Yamamoto and Aizen had begun.
"Captain Hitsugaya, it seems your luck has run out." Tōsen looked up at the cracks in his Bankai. He had been moments away from deactivating it. Moments away from having it shattered by Yamamoto's power. But that slight delay had sealed Hitsugaya's fate. Zanka no Tachi's flames would evaporate all moisture within the replica Karakura Town.
Hitsugaya's Zanpakutō was useless.
…
BOOM!
Flames erupted in the sky above the replica Karakura Town, a second sun blazing.
BOOM!
Aizen's spiritual pressure surged. The white cocoon surrounding him shattered, revealing his transformed form. The remnants of the cocoon reformed into a white haori that draped over his shoulders. His spiritual pressure had increased again.
"Aizen!" Seeing his opponent grow stronger after each attack, Yamamoto roared and charged again.
BOOM!
Aizen was sent flying, his body scorched by the flames, but regenerating almost instantly. Yamamoto, however, was tiring. The magma-like flames on Ryūjin Jakka receded, his spiritual pressure waning.
"Captain-Commander Yamamoto, you're too old!" Aizen's transformation was complete, he flashed before Yamamoto with his Zanpakutō descending.
BOOM!
Yamamoto raised Ryūjin Jakka to block, but Aizen's power, amplified tenfold, overwhelmed him. Weakened by exhaustion, Yamamoto reverted from his Bankai, his strength drastically reduced. He was sent crashing to the ground.
Aizen had won. Yamamoto, despite his valiant efforts, had been defeated. His age, his inability to sustain his Bankai, had been his undoing. Aizen, through sheer resilience, fueled by the Hōgyoku, had outlasted him, evolving twice in the process to match Yamamoto's power.
Aizen descended, preparing to deliver the final blow.
Shunsui Kyōraku, Jūshirō Ukitake, Soi Fon, Marechiyo Ōmaeda, Tetsuzaemon Iba, and Chōjirō Sasakibe appeared before the fallen Captain-Commander, shielding him from Aizen.
"Oh?" Aizen's lips curled into a faint smile. "Even Captain-Commander Yamamoto has fallen. Do you truly believe you can stop me?"
"Aizen, don't get ahead of yourself. We saw your fight. Yamamoto didn't lose to you. He lost to time. If he were a century or two younger, you would be ashes now." Kyōraku's Zanpakutō was already released,
"Indeed, Captain Aizen. Your boasts are… comical."
Kyōraku's words resonated with the other Shinigami. Yamamoto, until his exhaustion, had dominated the fight.
However, Kyōraku's claim that a younger Yamamoto could have defeated Aizen was wishful thinking. Merged with the Hōgyoku, Aizen was effectively immortal. And while Yamamoto's age had limited his stamina, it had also amplified his power. His attacks, while brief, had been devastating.