Traveling from Soul Society to the World of the Living didn't take long—opening the Senkaimon took a moment, sure, but actual traversal was quick. The real issue was that the gate couldn't open directly atop a battlefield.
So when Shiba Kaien and his squad arrived at the incident site, it had already become a playground for Hollows.
Everywhere he looked: towering beast-class Hollows, dozens of stories high, tearing apart unsuspecting humans, feasting like demons in a banquet of flesh.
"Damn it! You bastards! How dare you—?!"
He didn't hesitate.
"Beasts' bones strewn across the stars, spires of red crystal, wheels of steel—when they move, they are the wind; when still, the void. The clash of spears resounds through Hueco Mundo!
Hadō #63: Raikōhō!"
Kaien's Kido roared to life—but before it could land, a howling gale tore through its path, scattering it mid-air like candlelight in a storm.
"Shinigami, your opponent is me, got it?"
Hovering above the ruined cityscape, a Hollow with a white mask marked "No.3" and twin mini-hurricanes circling his body appeared with a grin.
Kaien stiffened.
He recognized it.
An Arrancar—Hollow with the power of a Shinigami.
He'd never been to Hueco Mundo himself, but stories of these beings had long circulated, especially after that noble massacre incident decades ago. He'd even been part of the cleanup team.
Back then, Soul Society feared the Arrancar enough to classify them above Vasto Lordes—and that was saying something.
He wasn't even Bankai-capable yet. A Vice-Captain like him couldn't possibly stand up to this.
This was Captain-level threat—minimum.
Still, Kaien didn't falter.
He drew his Zanpakutō.
"Nejibana—Flow, Twist the Waters!"
A spiraling trident took shape in his hand.
He wasn't leaving his squad behind.
As the other Hollows charged, Kaien spun his weapon.
"Sea and Sky as One!"
A curtain of water surged upward, stretching from earth to sky, separating the Shinigami from the beasts.
"Fall back!" he shouted. "This is beyond us. Someone must alert Captain Ukitake!"
Kaien knew: these new generation Shinigami—many had never seen Arrancar.
They didn't understand.
But even he underestimated the scale of the nightmare unfolding.
His Sea and Sky Barrier was powerful—far beyond average—but the Arrancar across from him, that No.3, stood silently. Unbothered.
Because behind them, standing directly in the Shinigami's escape path… was someone else.
A man so far above even that No.3 Arrancar, he dared not interrupt.
"Since you've come… you may as well stay."
The voice rang from above.
Coyote Starrk.
Primera Espada.
None of the Shinigami even saw him move.
It wasn't that they were blind.
They simply didn't have the chance to open their eyes.
In less than a second, he was among them.
No Resurrección. No Cero.
Just Sonído and spiritual pressure so dense it drowned thought.
One by one, they dropped dead—not even time to scream.
Only Kaien remained, staring into void.
"Two… Arrancar…"
A pale, defeated smile pulled at his lips.
What did I ever do to deserve this honor?
Even if Ukitake himself had come, he doubted this could've been handled.
Meanwhile, back in Soul Society—
Ukitake Jūshirō stood before Captain-Commander Yamamoto in the 1st Division barracks.
"You wish to go to the World of the Living?"
Yamamoto's gaze held restrained concern.
Just as Vice-Captains needed permission from their Division Captain, even Captains like Ukitake required the Commander's approval—and formal clearance from Central 46.
This was to prevent Captains from disrupting the balance between worlds.
Though truthfully, the rule was more symbolic than practical.
"My divination says Kaien's in danger."
Ukitake didn't hesitate.
"Divination, huh…"
Yamamoto muttered, rubbing his beard.
He knew Ukitake had strange talents—tied to something his family kept very quiet.
Still, his predictions were unnervingly accurate.
And this was Shiba Kaien they were talking about.
The Shiba Clan had lost prestige, yes—but they were still one of the Five Great Noble Houses.
Kaien wasn't just a promising Vice-Captain. He was the only successor left.
Yamamoto nodded.
"Permission granted. I'll notify Central 46 myself."
Ukitake left in a flash.
But Yamamoto didn't go to Central 46.
He went straight to the Shiba estate.
"Kaien… is in danger?"
The old man sitting opposite him looked ancient even by Soul Society standards.
Shiba Mura, patriarch of the family.
He had only two grandsons and one granddaughter left after centuries of war.
Yamamoto couldn't help but feel the weight.
"Ukitake's divination—it's rarely wrong. But I've already sent him to intervene."
"Alone?" Shiba Mura's tone darkened.
"Yamamoto… don't forget what happened ten years ago."
Ah, that.
The "official" record claimed a heroic Vice-Captain and a task force of investigators thwarted the incident.
But they both knew the truth.
It had been Kyōraku Shunsui, Yamamoto's own protégé, who begged the then-outlawed Higashi Shuuichi to act.
Without him, Kaien would've died that day.
And Shuuichi's criminal status? Conveniently cleared shortly after.
Coincidence?
Hardly.
"This time… are we walking the same path?" Shiba Mura whispered.
"Is someone trying to eliminate the Shiba Clan again?"
He looked at Yamamoto with bleak eyes.
"I mastered Bankai six centuries ago. That used up my life's talent. Since then, not one Shiba has awakened theirs.
Until Kaien.
He's our only hope.
If he dies…"
Mura's voice cracked.
"If you won't protect him for Soul Society's sake, do it for an old man's peace of mind.
Send more Captains.
And if Kaien falls… please look after Shiba Isshin from our branch family. He's the only other one who might reach Bankai someday."
Yamamoto didn't answer immediately.
But when he finally did, his voice was steel.
"Emergency Captain Meeting."
A Hell Butterfly fluttered from his hand, vanishing into the dark.
By dawn, nearly all Captains had assembled—except Ukitake, already en route, and the independent Higashi Shuuichi.
The meeting was curt.
Deploy more Captains to the World of the Living.
Which ones?
Reactions were mixed.
Many were outraged.
All this, over a Vice-Captain? The incident wasn't even confirmed.
To hold a full Captain's assembly, deploy more Captains, based on a prophecy?
Blatant favoritism.
In the old days, most Captains were nobles or close allies of noble houses.
But now?
After decades of upheaval, over half the Captains came from pure Rukongai backgrounds.
Still—Yamamoto pushed it through.
And the names chosen?
All tied to noble or military tradition:
Sui-Feng, 2nd Division
Kyōraku Shunsui, 8th Division
Komamura Sajin, 7th Division—his loyalty unquestioned
The only odd man out: Zaraki Kenpachi.
Pure chaos in a uniform.
The others didn't yet realize—
This was only the prelude.
After the meeting ended, Aizen Sōsuke and Ichimaru Gin departed together for breakfast.
Kurotsuchi Mayuri, on the other hand, returned alone to his underground lab.
His eyes glinted behind his mask.
The timing wasn't perfect, but it was close enough.
A rare window.
He opened a map of the World of the Living.
Kanda District, Karakura Town—that was where the incident occurred.
So he picked a distant city—Beihai—with plenty of human souls, far from Kanda.
Alone, he calibrated a Senkaimon.
He released three modified souls—prototype artificial beings long kept in stasis under heavy sedation.
He injected them with a final serum, then hurled them into the gate.
Senkaimon closed.
And the bacteria he'd embedded in their bodies would relay everything they experienced… directly back to him.
Mayuri Kurotsuchi smiled.
The chaos had only just begun.