"Zanki!"
After Shunsui Kyōraku called out the name of the game, he plummeted from the sky like a meteor with his twin Zanpakutō trailing flames from the air friction.
"Come!" Barragan Louisenbairn, having retracted his expansive miasma, focused it into his axe and lifted it to meet Kyōraku's descent.
BOOM!
The two forces collided mid-air with a thunderous explosion. Barragan, who moments before had been rocketing skyward, was driven back into the earth with several times the force of his ascent. The impact created a localized tremor.
Kyōraku hovered in the air, shaking his head. He'd anticipated a more challenging fight. He hadn't expected such a straightforward victory. Against Katen Kyōkotsu's rule-based abilities, as long as the opponent was within his spiritual pressure range and not overwhelmingly stronger, the rules were absolute.
Zanki amplified his attacks based on height. The higher he stood, the stronger the blow. This attack, launched from his highest vantage point in centuries, had been amplified tenfold. With that level of power, Kyōraku felt confident he could even bring down Captain Ailin.
Barragan, having foolishly met the attack head-on, was cleaved into three, his own Respira was unable to save him. He was dead.
Sensing the Segunda Espada's fading spiritual pressure, Kyōraku surveyed the battlefield. Ukitake, the bane of Kidō-type abilities, had completely countered Coyote Starrk's Infinite Cero.
Captain Hitsugaya had encased Tier Harribel in ice, and the remaining Arrancar subordinates had fallen to the lieutenants.
Hitsugaya now stood facing Gin Ichimaru. Sajin Komamura battled Kaname Tōsen, though he seemed to be struggling.
Kyōraku glanced at Captain Ailin. That fight was over. Neither Ailin, Kisuke Urahara, nor his allies showed signs of injury.
Should he assist Captain Komamura? Sensing his friend's resolve, however, he decided against it. Komamura wouldn't appreciate the interference.
"Well, it seems the battle is won. I think I'll take a break."
As the words left his mouth, another Garganta opened in the sky. A hulking, brutish Arrancar with a face contorted in a perpetual grimace, clambered out, roaring.
"Another Arrancar? And that spiritual pressure… how peculiar."
…
Back in Soul Society…
Reigai-Rukia sheathed her Zanpakutō, a gesture as elegant as the original's.
The ice pillar encasing Rukia Kuchiki shattered, shards of ice rained down. Anyone frozen by Sode no Shirayuki's "First Dance, White Moon" would be destroyed along with the ice.
Her Zanpakutō didn't attack with ice, but with cold itself. Ice could release cold, and cold could freeze water into ice, but the temperature of ice was warmer than the cold that created it. Anything caught in Sode no Shirayuki's initial freeze was already dead, its cells destroyed by the extreme cold. That was the terrifying power of Sode no Shirayuki.
This time, however, Reigai-Rukia had miscalculated.
"Second Dance, White Ripple!"
BOOM!
A familiar voice echoed from behind. A wave of even colder air engulfed Reigai-Rukia, freezing her solid.
Rukia emerged from the shattered ice pillar, frost coated her hair and eyebrows and her skin tinged with blue.
She had reached "negative one degrees." Realizing she was trapped within Sode no Shirayuki's range, she had instantly activated her Zanpakutō's true Shikai, lowering her body temperature to a degree colder than even her own "First Dance, White Moon." This prevented the cold from penetrating her body, protecting her from any real harm.
Having shattered the ice around her, she unleashed her "Second Dance, White Ripple," encasing Reigai-Rukia in ice.
Though tempted to finish her doppelganger, Rukia, sensing the clashes of spiritual pressure erupting between the Sixth and Ninth Divisions, turned and rushed towards the Sixth.
The situation was clear. Somehow, doppelgangers of the captains and lieutenants had appeared. She knew they were fakes. The real ones were fighting Sōsuke Aizen in the World of the Living. They couldn't be here. The appearance of her own double had confirmed her suspicions.
These imposters possessed strength comparable to their originals. Rukia quickly deduced that the real danger wasn't these fakes, but the genuine Shinigami remaining in Soul Society. They would be targeted.
The imposters' spiritual pressure had originated from the Twelfth Division. This meant Captain Mayuri Kurotsuchi was either the mastermind or had been compromised.
She sensed Captain Byakuya Kuchiki and Lieutenant Renji Abarai, both genuine, engaged in battle. They needed to regroup, find a safe place to hide, and wait for the others to return.
Reaching the site of Renji's fight, Rukia saw two identical figures, differing only in their injuries. How could she tell them apart?
"Rukia?" the more injured Renji asked, noticing her arrival.
"Are you… the real Renji?"
"Ha! Rukia! How did you know? I was about to ask you the same thing."
"Because I know that, regardless of whether I'm real or not, you would never raise your sword against me."
"Ah, you're right."
Before joining the Gotei 13, Rukia and Renji had been family, siblings bound by circumstance. They had protected each other, and the younger children who followed them, in the harsh realities of Rukongai, a district plagued by bandits, thieves, gangs, and the ever-present threat of Hollows.
One by one, their younger siblings had perished. It was this loss that had driven Rukia to join the Shin'ō Academy, to become a Shinigami. They shared a bond forged in hardship, a trust that transcended even this bizarre situation. Neither would attack the other without knowing for certain.
The one who had attacked Renji, then, had to be the imposter.
"Need any help, Renji?" Rukia asked. Though she couldn't bring herself to harm someone who looked exactly like Renji, she could restrain him long enough for the real Renji to finish him.
"Yes, please, Rukia." Renji knew he couldn't afford to be sentimental. They needed to defeat this imposter, find Captain Kuchiki, and formulate a plan.
Seeing them preparing to attack, Reigai-Renji grinned, raising his Zanpakutō.
"Bankai – Hihiō Zabimaru!"
BOOM!
An immense spiritual pressure erupted from him. His Zanpakutō transformed into a massive, segmented, skeletal snake, its head white with a red mane, like a Hollow's skull.
"He can even use Bankai?"
Though they had suspected it, seeing it confirmed shook them.
Renji stepped forward, preparing to release his own Bankai, but before he could, a cascade of cherry blossoms descended, engulfing Reigai-Renji.
"Go!"
Byakuya Kuchiki appeared beside them. With a single word, he turned and fled towards the Seireitei's edge.
Rukia and Renji followed, vanishing into the night.
…
"We should be safe here."
Byakuya had led them to a hidden training ground, the place where Ginrei Kuchiki, on his deathbed, had been brought by Ailin to use the Tenshintai, to master his Bankai. As Kisuke Urahara's secret base, it was unknown to the Gotei 13.
"Captain Kuchiki, who were those people?" Rukia asked, relieved to have escaped. "How could they have our spiritual pressure and Zanpakutō?"
"I don't know. But it's undoubtedly related to the Twelfth Division's SRDI."
"What do we do now?" Renji asked, scratching his head. "Should we infiltrate the Twelfth Division and investigate?"
"No. In our current state, that would be suicide. I'm more concerned about my aunt. I sensed Uncle Ailin's spiritual pressure among those imposters."
Hearing this, both Rukia and Renji lowered their heads. Ailin's presence had been the main reason for their hasty retreat. They felt confident against their own doppelgangers, but against Captain Ailin… escape had been their only option.
"Rukia, Renji, stay here and monitor the situation. I'll use the Kuchiki Clan's Senkaimon to go to the World of the Living and inform Captain-Commander Yamamoto. He needs to know what's happening here."
Byakuya drew his Zanpakutō, preparing to open the Senkaimon.
To his surprise, he couldn't sense the Dangai, the dimensional pathway between worlds. The Senkaimon was merely a key; it couldn't open a door that didn't exist.
"What's wrong, Captain?" Renji asked, seeing his captain's expression shift.
"It failed. I can't sense the Dangai. It seems the Twelfth Division has sealed all access to the World of the Living."
"So, we have to go to the Twelfth Division after all?" Rukia asked. "I don't know much about Captain Kurotsuchi, but Master Ailin always spoke highly of him. If we could escape, Captain Kurotsuchi must have as well. If we find him, we can contact the captains in the World of the Living."
Byakuya nodded. He had brought them here specifically to use the Senkaimon. Now, with that option gone, they had no choice but to infiltrate the Twelfth Division.
He couldn't risk Haruko Kuchiki being harmed. If anything happened to her, Ailin would undoubtedly retaliate.
"I'll go alone. Rukia, Renji, stay here and observe. If any captains return from the World of the Living or Hueco Mundo, bring them here. We'll regroup and plan our counterattack."
"Yes, Captain Kuchiki."