Ryūjin Jakka was the strongest fire-type Zanpakutō.
Then Kuruyashiki Kenpachi's Zanpakutō, Gagaku Kairō, could be called the "strongest biological-type Zanpakutō."
Its Bankai's destructive power and range were considered the greatest among all Zanpakutō.
Once Kuruyashiki released his Bankai, a city the size of Karakura Town would be instantly annihilated.
It was a destructive range that even Kuruyashiki himself couldn't control.
If Ailin's "past self" had possessed Gagaku Kairō back then, the battle against Iskandar, the King of Conquerors, wouldn't have dragged on for so long.
Simply releasing Gagaku Kairō's Bankai would have been enough to instantly kill Iskandar along with the fifty thousand soldiers within his Reality Marble.
Of course, with such immense power came a significant drawback.
After releasing Gagaku Kairō's Bankai once, Kuruyashiki needed half a year before he could release it again.
During this six-month period, Gagaku Kairō would fall into a deep slumber, rendering even its Shikai unusable.
Naturally, for Ailin, such a powerful Zanpakutō, even with such a severe side effect, was acceptable.
Moreover, this was merely Gagaku Kairō's original flaw.
With Ailin's modifications, the duration of Gagaku Kairō's slumber could surely be significantly shortened, among other potential improvements.
Eager to find this powerful Zanpakutō within Unlimited Blade Works, Ailin bid farewell to Jūshirō Ukitake, returned directly to his home, and used Zazen to enter his inner world.
...
Black, red, and gold light intertwined and flickered within the space.
The golden spiritual pressure dominated, while the black and red energies swirled around it.
The golden spiritual pressure was Ailin's own.
The black spiritual pressure was the magical energy from the Holy Grail brought back from the Type-Moon world by his "past self." It had been completely fused with Hollowed Lin, becoming the foundation of his existence as the "Third Magician."
The red spiritual pressure belonged to Hollowed Lin himself, the power he gained after being transformed into a Hollow by the Hōgyoku.
Should Ailin require Hollowed Lin's power, both the black and red spiritual pressures would immediately merge into Ailin's golden energy, causing a qualitative change in his power and elevating him to a higher dimension.
Ailin's figure suddenly materialized within Unlimited Blade Works, standing atop the highest point of the Sword Hill.
Upon Ailin's appearance, the black spiritual pressure solidified, coalescing into the form of Hollowed Lin, who asked Ailin warily.
"Ailin, what are you doing here?"
Although Hollowed Lin had been defeated by Ailin and, according to their agreement, had become the "mount" that augmented Ailin's strength, Ailin's own power was usually sufficient to handle external threats.
Perhaps only when facing opponents like Ichibē Hyōsube or a fully realized Yhwach would Ailin need to draw upon Hollowed Lin's spiritual pressure to boost his own strength.
Therefore, Hollowed Lin's current situation was practically unchanged from before.
Of course, as Ailin's "mount," Hollowed Lin also had a new long-term task: to tirelessly draw swords for Ailin, identifying the Zanpakutō within Ailin's inner world that Ailin himself hadn't yet recognized, learning their names, truly making them part of Ailin's arsenal, and thus increasing Ailin's spiritual pressure.
In Hollowed Lin's view, with him helping Ailin draw swords, Ailin shouldn't need to appear here without reason.
Usually, Ailin's appearance here meant he wanted to spar.
Hollowed Lin did indeed wish to defeat Ailin and become the dominant consciousness, but that didn't mean he was unaware of the power gap between them.
No one enjoyed getting beaten up every day.
"Relax, Hollowed Lin."
"I didn't come here this time to fight you."
Hearing Ailin's words, Hollowed Lin breathed a sigh of relief.
However, he immediately put on a tough front: "Hmph, don't make it sound like I'm afraid to fight you."
"Oh? Then perhaps we should have a round first?"
Ailin looked up, only to see Hollowed Lin's expression change abruptly. "Forget it. Since you came here for something specific, if I delay you, you'll just use it as an excuse for losing to me later, and I won't be able to refute it."
With that, Hollowed Lin's figure dissolved back into black spiritual pressure, merging into the surrounding dark energy. This sludge-like, tangible spiritual pressure slowly spread through Unlimited Blade Works, disappearing from Ailin's sight.
Ailin paid Hollowed Lin no mind.
He closed his eyes, extending his spiritual awareness, completely merging it with the entirety of Unlimited Blade Works.
All the Zanpakutō were now within his perception.
Then, Ailin extended his right hand and called out—
"Born from slaughtering auspicious omens, respecting the gloom and bidding farewell to aging…"
"Answer my call, Gagaku Kairō!"
Boom!
As Ailin shouted Gagaku Kairō's release command, a surge of black spiritual pressure instantly erupted from one of the countless Zanpakutō embedded in the ground within Unlimited Blade Works.
Subsequently, this Zanpakutō transformed directly into a dozen or so white, round creatures the size of brown bears, looking surprisingly cute and harmless.
Uneven black markings adorned the bodies of these bear-sized white spheres.
Suddenly, the jagged markings on one of the white spheres split open—the black spikes were revealed to be the creature's sharp teeth.
These white spherical beings could apparently open their mouths to cover more than four-fifths of their own surface area, capable of devouring everything within a nearly three-hundred-degree range around them.
These dozen or so bear-sized spherical creatures, having answered Ailin's call, had now become another new Zanpakutō in his possession.
Under Ailin's control, these dozen white spherical creatures didn't randomly attack the turbulent space around them. Instead, they flew to the top of the Sword Hill, circled around Ailin a few times, then reverted to the form of an ordinary Asauchi, embedding itself in the Sword Hill beside Ailin.
And next to Gagaku Kairō stood Ryūjin Jakka, Hyōrinmaru, Gonryōmaru, and other Zanpakutō belonging to the "Strongest Series."
Even with Ailin's current power, a Zanpakutō from the Strongest Series still provided a very significant boost.
Placing his hand on Gagaku Kairō's hilt, Ailin began to synchronize with it.
Golden patterns spread from Ailin's hand across Gagaku Kairō.
Soon, Ailin completed the synchronization with Gagaku Kairō, reading the memories of the Seventh Kenpachi, Kuruyashiki Kenpachi, regarding its use.
To Ailin's surprise, Kuruyashiki's mastery of swordsmanship was even greater than he had anticipated.
Of course, Ailin could understand this.
After all, Kuruyashiki's Zanpakutō ability was excessively powerful; its Bankai was forbidden within the Seireitei, and even releasing it outside incurred a half-year cooldown.
Therefore, Kuruyashiki's strength relied heavily on swordsmanship as his primary means of attack.
His ability to slay Vasto Lorde-class Hollows without releasing his Zanpakutō was a testament to his swordsmanship proficiency.
After reading Kuruyashiki's memories of using Gagaku Kairō, Ailin's own swordsmanship improved slightly.
More importantly, Ailin gained a deeper understanding of Gagaku Kairō.
Gagaku Kairō was a biological-type Zanpakutō. Its release, somewhat similar to an Arrancar's Resurrección, allowed the Zanpakutō to manifest in its true form.
This Zanpakutō's Bankai had only a single strike.
Once released, it would devour, tear apart, and pulverize all existence within half a Ri, excluding its master.
The reason for the half-year cooldown was that Gagaku Kairō needed time to completely digest what it had swallowed.
In terms of attack power, this ability was practically maxed out; Ailin saw no need for adjustment there.
However, regarding the devouring, tearing, and pulverizing aspects, Ailin could add some powerful abilities to Gagaku Kairō, enhancing these characteristics and shortening its cooldown period.
"Synchronization—Begin!"
Having formulated a plan, blue patterns of spiritual pressure continued to spread from Ailin's hand across Gagaku Kairō.
The previous golden patterns were for synchronizing with Gagaku Kairō, reading its master's memories and usage methods.
The current blue spiritual pressure patterns represented Ailin using his own abilities to adjust Gagaku Kairō's powers.
Ailin made no changes to Gagaku Kairō's attack method or range.
His main focus was integrating the spatial power of the Royal Seal, the shattering power of Bakusaiga, the demon-breaking power of Benihime, and the destructive power of several other potent Zanpakutō into Gagaku Kairō.
When Ailin finished adjusting Gagaku Kairō and synchronized with it once more, he nodded in satisfaction.
After Ailin's adjustments, Gagaku Kairō's cooldown period had been reduced from six months to just one month.
This meant Ailin now had another trump card in his hand.
...
Rumble!
Rolling dark clouds gathered above the 12th Division barracks. The next moment, countless bolts of lightning rained down from the clouds, striking towards Squad Twelve.
The sheer force of this attack created a massive commotion. Within the Seireitei, any Shinigami with the spiritual pressure of a seated officer or higher could sense the terrifyingly violent energy that made their hearts tremble.
"This is the spiritual pressure of Squad One's Vice-Captain, Chōjirō Sasakibe."
In the Squad Five captain's office, Ailin and Vice-Captain Momo Hinamori stepped out quickly, looking towards the distant dark clouds and lightning.
"Eh? Vice-Captain Sasakibe?"
Hinamori was extremely surprised by Ailin's words.
Honestly, Chōjirō Sasakibe was a notable figure within the Gotei Thirteen. After all, not every vice-captain could achieve his level.
Serving under Genryūsai Shigekuni Yamamoto, he perfectly concealed his own brilliance, becoming the Captain-Commander's shadow.
If Shunsui Kyoraku and Jūshirō Ukitake were Yamamoto's most outstanding disciples, then Chōjirō Sasakibe was Yamamoto's most trusted and reliable disciple and subordinate.
Every Shinigami in the Gotei Thirteen knew Chōjirō Sasakibe was the Captain-Commander's vice-captain.
However, when things were calm, people usually forgot how powerful Chōjirō Sasakibe truly was.
No, it would be more accurate to say that Chōjirō Sasakibe generally had little presence in the minds of most Shinigami.
"Vice-Captain Sasakibe is actually this strong!"
"Of course."
Ailin clearly knew the impression Chōjirō Sasakibe left on other Shinigami, so he wasn't surprised by Hinamori's reaction.
"He is the Captain-Commander's vice-captain, after all..."
"Also, one of the 'X'-shaped scars on the Captain-Commander's head was inflicted by Vice-Captain Sasakibe."
"Hiss..."
Hinamori gasped sharply, looking towards the lightning-struck Squad Twelve barracks.
"Since Vice-Captain Sasakibe is so strong, then the 12th Division..."
"Relax..."
Ailin ruffled Hinamori's hair and smiled reassuringly. "That's Captain Mayuri Kurotsuchi's territory."
"Although Captain Kurotsuchi's direct combat ability isn't considered top-tier among the captains. But give Captain Kurotsuchi some time, and he can defeat most enemies in this world."
He said "most" because individuals like Ailin, Ichibē Hyōsube, and a fully realized Yhwach were beyond Mayuri's reach. No matter what tools Mayuri created, they would be ineffective against beings of such a different dimension.
The disparity in dimensions couldn't be erased by mere tricks.
It was similar to the final battle between Aizen, Ichigo, and others against Yhwach. Regardless of their preparations, victory ultimately relied on Ichigo Kurosaki—who had fused the powers of Quincy, Shinigami, Hollow, and Fullbring, elevating his spiritual pressure dimension—to deliver the final blow.
If Ichigo's own spiritual pressure hadn't reached Yhwach's dimension, neither Aizen's Kyōka Suigetsu nor the silver arrowhead crafted from the remnants of "Auswählen"-purged Quincy (designed by Ryūken Ishida and Isshin Kurosaki to temporarily negate Yhwach's Almighty) would have amounted to more than a scratch against Yhwach.
Furthermore, such an opportunity was unique. Once these countermeasures were revealed, Yhwach's "Almighty" would comprehend their secrets, allowing him to eliminate them in the future before they could pose a threat.
Excluding Ailin, Ichibē Hyōsube, and Yhwach, however, anyone targeted by Mayuri could be countered; Mayuri was fully capable of creating something to neutralize them.
Indeed, just as Ailin expected.
Before the lightning could strike Squad Twelve, metal rods emerged from the rooftops. Aided by spiritual pressure, these rods directly drew down Gonryōmaru's lightning, channeling and storing it through a series of devices. Squad Twelve emerged from the attack unharmed.
From the moment the Reigai appeared, Mayuri knew a battle against these replica captains was possible.
Fortunately, Mayuri routinely researched other captain-level powerhouses and had contingency plans for facing them.
The past two weeks had provided ample time for Mayuri to implement these plans.