"Aren't you going to help your master?"
"Don't worry, I won't kill you."
"A fight that ends in a single moment isn't even worth watching. Besides, there's no opponent in Soul Society who can make both of us draw our blades at the same time."
Aizen spoke calmly, hands tucked in his sleeves, while Muramasa stood tensely in front of him with a drawn sword.
"Do you think I'd believe that, Aizen?"
Though Aizen declared he wouldn't interfere, Muramasa stayed locked onto him, refusing to lower his guard. He obeyed Kōga's command without hesitation, eyes never leaving Aizen's form—after all, both he and Kōga had just been toyed with by Kyōka Suigetsu's illusions not long ago.
Who could possibly believe him now?
"Aiyan, don't underestimate me."
On the opposite side, Kōga gripped his Zanpakutō tightly, his Reiatsu bursting forth like raging tides. The pressure stirred the ground beneath him—stones cracked, dust lifted, the atmosphere vibrated.
"Hadō #57: Daichi Ten'yō!"
With a loud chant, flames erupted at the tip of Kōga's blade, forming a blazing red sphere like a miniature sun. The fireball tore through the air, roaring toward Aiyan.
"You know,"
"It's not that I'm underestimating you."
"It's just—I don't see you at all."
Aiyan's eyes never turned toward the incoming fireball. Instead, he lifted his head to look at the sun hanging high in the Soul Society sky.
"It's noon."
The moment those words fell, a blinding golden pillar of light shot down from the heavens, engulfing Aiyan entirely. His white captain's haori shimmered in gold, radiating divine brilliance.
Hiss—
The heat beneath him instantly turned stone to molten red, smoke curling up as the earth melted underfoot. And yet Aiyan made no move. He simply stood, and his presence alone caused the atmosphere to burn.
The sheer Reiatsu—oppressive, scorching, divine—made even Aizen, watching from the sidelines, feel a chill crawl down his spine.
It was the same pressure he'd once felt only from Yamamoto Genryūsai.
"What… what is this power…?"
Aizen's glasses reflected the radiant golden flare, and even he was momentarily stunned. He had known that Aiyan's Zanpakutō was the strongest dual-nature type—of both light and darkness.
But this…
This was the first time he had ever seen it unleashed.
Bathed in that golden light, Aiyan stood like a sun god, shining over Soul Society.
"Huu—"
Aiyan turned toward the incoming fireball. He didn't draw his Zanpakutō. He didn't raise a hand.
He simply… blew.
Fwoo—
Like blowing out a candle.
The roaring fireball, bursting with heat and Reiatsu, fizzled in an instant—disintegrating mid-air with a puff of smoke.
"What...?"
"What kind of ability is this?!"
Kōga's expression twisted in disbelief.
One moment he thought he understood—Aiyan's Zanpakutō was darkness-based. Then Muramasa had claimed it could manipulate time.
And now it appears to be the embodiment of the sun itself.
He couldn't grasp it. He couldn't read Aiyan's power at all.
"Didn't I already tell you?"
"Zanpakutō: Kōfūin. The strongest in both light and darkness."
Aiyan slowly unsheathed his sword.
"Shikai: 'Throne of Heaven, Rule of One.'"
The moment he spoke, the blade in his hand began glowing like a divine relic—blazing with golden heat, brighter than the sun itself.
Aizen, still watching calmly, narrowed his eyes.
"So that's what it is… Kōfūin—is both light and dark. If the shining version's strongest Shikai is 'Rule of One.,' then doesn't the dark version also have its own ultimate Shikai ability?"
A gleam of interest sparked in Aizen's eyes.
"Far stronger than I imagined."
"A Zanpakutō like this… how can Soul Society even allow it to exist?"
Kōga swallowed his fear and raised his Zanpakutō.
He wasn't giving up.
"Bakudō #26: Kyokkō."
Dark shadows burst from beneath his feet, splitting into dozens of tendrils that lashed out to bind Aiyan's shadow.
At the same time, a cold swept in.
Kōga raised his Zanpakutō high, unleashing a freezing blast of spiritual energy. In mere seconds, the surrounding terrain began to freeze—the slopes outside Sōkyoku Hill now buried beneath frost and snow.
A white dragon of frost lunged at Aiyan.
"Better than that fireball earlier," Aiyan said, his tone casual.
"But still…"
He raised his left hand.
Only one finger extended.
Boom—
A deafening impact.
With just one finger, Aiyan stopped the giant frost dragon in its tracks. The blizzard froze around him, unmoving, trembling.
Then that finger touched the ice.
Fsssh—
The frost shattered and evaporated instantly, golden heat melting it into steam with a single touch.
"Had enough?"
Zzzt—
Dozens of golden beams descended from above, like piercing lasers—firing at Aiyan in rapid succession.
Boom—
A tremendous explosion erupted. A beam of concentrated Reiatsu enveloped Aiyan entirely.
"That's the price for looking down on me… Aiyan Sōsuke."
Standing at a distance, Kōga glared coldly at the tower of Reiatsu light shooting into the sky.
"You should have listened."
A calm voice echoed from within the golden pillar.
Then—shhhhhh—
The beam split down the middle, like curtains pulled back for royalty.
Aiyan stepped out, completely unharmed.
He raised his blade.
"Please refer to me properly—from now on, it's Captain Aiyan."
He lifted his sword skyward.
Boom—
The moment the blade fell, a cataclysm descended. Golden sword pressure rained down like a divine storm, tearing through the landscape of the execution ground.
"Bakudō #81: Dankū!"
Kōga's face froze in terror.
He abandoned chanting and force-cast a high-level Bakudō, creating a massive energy wall of splitting void in front of him.
'My Dankū can block Hadō #89… One sword shouldn't be a problem.'
He tried to reassure himself.
But—
Crack—
A sharp splintering echoed out.
Hairline fractures webbed across the Dankū wall like a shattered mirror. The golden sword beam hadn't even fully landed yet.
Kōga's breath caught in his throat
"No—!"
Muramasa's eyes widened. No longer caring about Aizen, he dashed to Kōga's side, blade raised to intercept.
Boom—
The wall of splitting void shattered completely.
The golden sword wave descended like a tsunami, engulfing both Shinigami and Zanpakutō in an endless sea of light.