Onepiece: I Am Aizen, The Strongest Admiral

The moment Aizen removed his glasses, it was as though a hidden switch had been flipped, unleashing a fierce and commanding aura. His previously mild-mannered demeanor gave way to the cold, calculated air of a ruler, exuding dominance and ruthlessness.

"Use the power of this Hōgyoku fragment," Aizen muttered, his voice calm yet filled with authority. He cast a casual glance at the fallen body before slowly extending his palm.

The perfectly round shard of the Hōgyoku seemed to defy physics, descending from his hand at an unnaturally slow speed before sinking into the chest of the lifeless pirate.

A sickening hiss filled the air as the corpse began to decompose rapidly. White foam bubbled from the pirate's wounds, eyes, mouth, and ears, spreading across his body in a grotesque display.

It was a nightmarish sight—one that would unnerve even the bravest witness. The transformation appeared to defy the natural order of the world, as though some monstrous entity was being born.

The white substance enveloped the entire body, encasing it like a cocoon. Only the glowing Hōgyoku fragment remained visible at the center of the chest, pulsing like a beating heart.

"Just as I expected," Aizen remarked, observing the process with clinical detachment. "The spirit particle concentration in this world is far too low. Without the Hōgyoku fragment, the transformation would result in death. Still, it makes me wonder... could someone like Big Mom withstand the Hollowfication process without assistance?"

His musings shifted momentarily to Big Mom, the Soul-Soul Fruit user. If anyone could survive such a transformation naturally, it might be her.

After nearly thirty minutes, the process concluded. The pirate's body stopped emitting foam and began to take on its new form. What emerged was a towering creature, four to five meters in height, with a grotesque, skeletal frame and a mask covering its face. The Hōgyoku fragment remained embedded in its chest, radiating an eerie light.

"An Adjuchas-level Hollow... Impressive," Aizen muttered, a trace of approval in his voice.

Adjuchas-level Hollows were a significant step below Vasto Lordes, but still incredibly powerful. In Hueco Mundo, the number of Vasto Lordes was exceedingly rare, with only a few such as Baraggan, Harribel, and Ulquiorra ever reaching that level.

For this pirate to evolve directly into an Adjuchas-level Hollow upon transformation spoke volumes about his potential. Given time, he could very well ascend to the coveted Vasto Lorde tier.

The creature let out an earth-shaking roar, its Reiatsu materializing as a suffocating, blood-red aura.

"Still feral, despite reaching the Adjuchas level?" Aizen remarked, unfazed by the display of power. "It seems the process here differs from Hueco Mundo. No matter... That's why precautions are necessary."

He rolled up his sleeve, revealing a device resembling a wristwatch. With a press of a button, the monster's body turned bright red, radiating intense heat as it writhed in agony.

"Stay still," Aizen ordered, his voice icy. The creature thrashed violently, clawing at the ground in an attempt to resist, but it was futile.

After a few moments, Aizen released the button, and the Hollow slumped to the ground, its energy completely drained.

"Much better." He adjusted his glasses, his tone as calm as ever. "Another ten seconds, and you would have disintegrated entirely, leaving only the Hōgyoku shard behind. Remember that before trying anything foolish."

The creature remained motionless, its instincts recognizing the danger of defying its creator. Aizen's control over it was absolute.

"You're not complete yet," Aizen continued, studying the Hollow with a critical eye. "To evolve further, you'll need to consume more souls."

He turned and walked toward the exit, issuing orders to the prison guards through Kyōka Suigetsu's illusion. "Transfer three or four prisoners to the lower level daily."

Under the influence of Aizen's Zanpakutō, the guards believed they were simply relocating prisoners. They remained oblivious to the monster lurking in the depths of the prison or the fact that the 400-million-bounty pirate Neia had ever been incarcerated there.

As he left the prison, Aizen's thoughts drifted. Even if his actions were discovered, he was confident in his ability to manipulate the situation, placing the blame elsewhere if necessary.

*"Just as Hirako and the others were cast out of the Soul Society, turned into fugitives... If it comes to it, I'll make them believe the same story here."*

For now, the Adjuchas remained in its pit, feeding on the prisoners it was given. And Aizen's plans continued to unfold, one calculated step at a time.