Seeing that Aiyan was affected by Sakanade's ability, Hirako Shinji believed he had the upper hand. Aiyan didn't even try to draw his Zanpakutō—he stood still, cautious and unmoving.
With the sound of a blade slicing through flesh, Hirako Shinji had already closed the distance. His Zanpakutō had pierced through Aiyan's abdomen and out the back of his spine in one fluid motion.
Just as Hirako had said earlier—when Aiyan was under the influence of Sakanade, even a careless swing became a nightmare.
"Understand now, Aiyan Sōsuke?"
"This is the price for overestimating your strength—and for underestimating a Gotei Captain."
Shinji leaned closer, whispering those words coldly near Aiyan's ear.
He thought the battle was decided—his strike had landed perfectly. However, outside the Kidō barrier, the expressions of Unohana Retsu, Shiba Isshin, and Chōjirō Sasakibe had grown strange.
There was no alarm—just amusement, pity, even a hint of mockery in their eyes.
"You idiot... you're not even holding a sword!"
Sarugaki Hiyori's voice rang out clearly from outside the barrier, snapping Shinji out of his moment of triumph.
He quickly leapt back and looked down at his own hand—just like Hiyori said, the blade that had "pierced" Aiyan's abdomen wasn't stained with blood. Instead, it was covered in a strange black mist, leaking from the wound.
"Is this your Shikai, Captain Hirako?"
"I thought it was impressive at first."
"But in the end, it's just a child's trick."
Despite being 'stabbed', Aiyan was smiling—not in pain, but amused. He calmly reached out toward Shinji's wrist, seemingly to grab it. But under Sakanade's inversion effect, up became down, and forward became backward—so instead of grabbing, his movement turned into an awkward elbow strike in the opposite direction.
"Don't forget, you're still inside my inverted world," Shinji said smugly.
"For someone like you—who relies on instinctive combat—the more skilled you are, the more you'll suffer under Sakanade."
"Even simple actions like dodging, blocking, or attacking... your instincts will betray you."
"You'll have to consciously think through every movement... and no one can survive a battle like that."
Shinji chuckled, maintaining distance while taunting Aiyan.
"All it takes is one basic attack to deal with you now."
But before he could continue, Aiyan calmly pulled his hand back. His right palm now faced forward, fingers spread wide.
"Kuroimizu (Dark Water)."
Aiyan's hand turned into a swirling black vortex. An enormous gravitational force erupted outward, distorting the air around them. Even the barrier that Captain Shiba had set up warped violently under the pressure.
And Hirako Shinji, caught in its pull, could barely react.
It felt like he was being dragged into a black hole. The force was absolute, unstoppable.
Hadō or Bakudō? No time.
Even moving a finger required a massive effort of Reiatsu and strength—he was completely immobilized.
His only choice... was to stop resisting.
He was pulled toward Aiyan's palm—completely defenseless.
'But I still have a chance!' Shinji told himself.
'In this reversed world... he's inverted too. Even his attacks are reversed!'
'If I time it right, when he hesitates for even a moment... I can counter!'
That was his last thought—before he was dragged right up to Aiyan's outstretched hand.
He suddenly realized something terrifying.
"Where's my Shikai!?"
"My Sakanade... it's gone!"
"What!! is it... sealed!?"
Shinji's eyes darted down to the Zanpakutō in his own hand.
The curved blade and circular guard of Sakanade had vanished—what remained was just an ordinary, unawakened Zanpakutō.
Unbelievably, Shinji looked up at Aiyan in shock.
"Did you... seal my Shikai...?"
Aiyan, still gripping him with one hand, looked down from above and smiled.
"It seems you've finally noticed."
"Indeed... I know how to do Shikai as well."
"Your eyes are finally correct, Hirako-taichō."
"If you survive this, remember this feeling."
"Whenever you look at me in the future—use this gaze."
Without another word, Aiyan drew his blade with his other hand and, just like Shinji had done before, drove it straight into the captain's abdomen.
With one smooth thrust, the blade exited through Shinji's back. He gasped, blood pouring from both his stomach and mouth.
"You... what did you do to me...!?"
"Why did my Sakanade cancel on its own!?"
"I didn't release it!"
Shinji's voice was shaking, pale and confused.
But Aiyan only responded coolly.
"With your intelligence, I didn't expect you to ask such a basic question."
"Or maybe... the truth is so terrifying that your mind rejects it?"
"You already know the answer."
"You just don't want to believe it."
Aiyan's tone sharpened as he tightened his grip.
"I sealed your Shikai."
"Just like you were back when you first received your Zanpakutō."
Shinji's eyes widened in horror.
Outside the barrier, the faces of Unohana, Isshin, Sasakibe—and over six hundred other Shinigami—shifted.
Stunned silence followed.
That's because sealing a Shinigami's Shikai… is unthinkable.
The Zanpakutō is the very soul of a Shinigami.
To force it back into a sealed state—against the user's will—was something that even Yamamoto Genryūsai hadn't done.
Yet Aiyan had done it.