Kurotsuki Renya's body collapsed and reformed in cycles beneath the violent surge of lightning coursing through him. Flesh tore apart under the strain of his own Reiatsu, only to regenerate instantly under the influence of the Hōgyoku embedded within him.
The jewel responded to his will.
It did not merely react, it interpreted.
And so, it continued to evolve him.
Under its influence, a white substance began spreading across Renya's body. It crept over his arms, his torso, his face, smooth and bone-like, reminiscent of an Arrancar's mask fragment, yet far denser. Within moments, he was entirely encased.
This was the Hōgyoku's second metamorphic state.
A chrysalis.
Renya stood there, wrapped in hardened white armor, like a being suspended between humanity and transcendence.
His physical strength surged again. The ground beneath his feet cracked without him exerting force. The surrounding air distorted under the pressure of his Reiatsu.
Harribel instinctively steadied herself.
Ginjo narrowed his eyes.
Tsukishima's expression sharpened.
Even without releasing a Zanpakutō, Renya's spiritual pressure alone was enough to suffocate lesser beings.
This was not a simple increase in Reiatsu.
It was qualitative evolution.
His Reiryoku density had risen to a level approaching transcendence
nearing the threshold Aizen had reached in the Dangai after fusing with the Hōgyoku. Not yet beyond Shinigami limits, but pressing against them.
There were no "levels" to measure this.
Only one truth:
He was nearing the boundary that separated Shinigami from something greater.
Yet he was not there.
The Hōgyoku had halted its vertical transformation.
Instead, it refined him horizontally.
Muscle density compressed. Spiritual pathways expanded. Regenerative capacity accelerated. His Reiatsu became more controlled, less wasteful, more absolute.
At this stage, Aizen had already abandoned reliance on Zanpakutō abilities or Kidō, crushing opponents with sheer spiritual supremacy.
Renya was not yet that being.
Aizen, at his peak evolution, had surpassed the framework of Shinigami entirely.
Renya had only just stepped onto that road.
He slowly lowered his Zanpakutō and descended to the ground.
The instant his feet touched the sand of Hueco Mundo, a wave of spiritual suppression radiated outward.
It was not intentional.
It was instinct.
Harribel's eyes hardened as she felt the pressure.
"He's changed," she murmured.
Ginjo clicked his tongue. "That Reiatsu… he's not even trying."
Tsukishima adjusted his glasses slightly. "He's drifting away from being human."
Renya could feel their gazes.
He did not blame them.
At this distance, he barely recognized himself.
Then
A bright laugh shattered the tension.
"Renya! What happened to you?!"
Nelliel Tu Odelschwanck appeared beside him, clutching her stomach as she laughed openly.
Renya's masked face turned toward her.
"Be quiet."
"This is evolution," he said flatly. "I'm stronger than before."
Nelliel tilted her head and reached out, tapping the hardened white layer covering his forehead.
"So this shell is part of it?"
"Don't touch it," he snapped, swatting her hand away.
She grinned.
"You can't stay like this forever, can you? You look ridiculous."
Renya's Reiatsu flared faintly.
"My appearance is none of your concern."
"But you're our leader," Nelliel replied, crossing her arms. "If you walk around looking like that, we'll lose all dignity."
He froze.
Slowly, he looked around.
Harribel had already turned away.
Ginjo was yawning as if bored.
Tsukishima followed silently.
Ulquiorra watched him a moment longer, emerald eyes unreadable — then Sonído carried him into the darkness.
Renya stood there, abandoned.
"…Am I truly that strange?"
Silence answered him.
Nelliel leaned closer, peering through the narrow visor of white covering his eyes.
"I won't laugh anymore," she said softly.
"Leave."
His voice echoed across the desert.
Later, within Las Noches, Renya stood before a mirror.
The reflection staring back was barely human.
The chrysalis armor concealed his features completely smooth, pale, alien.
The next evolution would shatter this shell.
But beyond that…
The Hōgyoku's later stages, as seen in Aizen, had erased humanity altogether.
Would he become something unrecognizable?
Would those he cared for Rukia Kuchiki, Renji Abarai, the Gotei 13 still see him as Renya?
Or as a threat?
His heart wavered.
And the moment it did
The Hōgyoku responded.
The evolution slowed.
Just as it had with Aizen when his subconscious desire to remain on equal footing with Ichigo had restrained his transformation.
The Hōgyoku did not grant power blindly.
It manifested the heart's truth.
Renya closed his eyes.
"No."
"I did not seek strength for dominion."
"I did not seek transcendence for pride."
He thought of Seireitei.
Of comrades who had bled beside him.
Of bonds forged in battle.
"I will protect this world."
"If evolution is the path required, then I will walk it."
His resolve crystallized.
The Hōgyoku answered.
Reiryoku surged again steadier this time, controlled, absolute.
The chrysalis hardened further, nearing its breaking point.
Renya opened his eyes.
They burned with clarity.
He tapped a communication device adapted for Hueco Mundo transmissions.
"Grimmjow."
In an instant, Grimmjow Jaegerjaquez appeared, kneeling despite the instinctive tremor in his body under Renya's Reiatsu.
"Summon all Arrancar loyal to us," Renya said calmly. "We leave Hueco Mundo in three days."
Grimmjow's grin flickered.
"…Heh. Finally."
"Yes, sir."
He vanished in a blur of Sonído.
Far away, within the Seireitei.
In the Twelfth Division's laboratories, Mayuri Kurotsuchi observed fluctuating spiritual readings on layered monitors.
His painted smile widened.
"So it has fused further…"
The data spiked erratically.
"Hōgyoku assimilation approaching unstable thresholds. Fascinating."
He licked his lips thoughtfully.
"This warrants observation."
Mayuri turned sharply, his captain's haori swaying.
He would report to the Captain-Commander.
If Renya had truly begun transcending Shinigami limits…
Then the balance of the worlds was about to shift again.
And Mayuri intended to be present when it did.