A Side Story Within the Kōtotsu  

After all, based on the surveillance footage, Captain Ailin had obeyed his command, using the Kōtotsu within the Dangai to travel to the past and eliminate Aizen's Mod Soul.

"Captain Ailin, our preparations aren't complete yet. Now isn't the time to reveal ourselves, eliminate the originals, and seize control of the Seireitei. However, due to a recent oversight, one of the captain's Reigai has rebelled. To prevent it from exposing us, I had to ask you to travel to the World of the Living and eliminate it."

"Oh?"

Ailin's Reigai, satisfied with his appearance, adjusted his gaze.

No, there was no need for adjustment.

With this nearly invincible power and his memories of the world, he was a god!

With this shift in mindset, his gaze naturally became cold and indifferent.

Currently, there were only three individuals in this world he considered worthy of his attention.

No, to be more precise, only one.

After all, both the Hōgyoku-fused Aizen and the Almighty-wielding Yhwach were still decades away from reaching their full potential.

For now, only the one residing high above the Seireitei, within the Soul King Palace, the original Shinigami, could truly challenge him.

Hearing Inaba's explanation, he asked casually, "You've been careless? Which captain's Reigai rebelled?"

"It's the Reigai of Sōsuke Aizen, the captain of the Fifth Division."

"Captain Aizen, he's not a simple individual."

"Oh? Him? That's not surprising."

Inaba had intended to elaborate on Aizen's power, but seeing Ailin's reaction, he realized it was unnecessary.

"Captain Ailin, you know Captain Aizen?"

"Yes, besides Head-Captain Yamamoto, Sōsuke Aizen is the only one in the Gotei 13 I consider worthy of my attention."

"Oh?"

Hearing Ailin's high regard for Aizen, Inaba couldn't help but ask, "Captain Ailin, can you handle him?"

"Hah? What nonsense are you spouting?"

Ailin's Reigai glared at Inaba, his displeasure nearly forcing the researcher to his knees. "Aizen might be strong, but he's still within the realm of a 'Shinigami.' I've already transcended those limits, reaching a higher dimension. That mere Aizen, I can crush him with a single hand!"

While Inaba didn't understand what "a higher dimension" meant, Ailin's Reigai had indeed displayed overwhelming power in the surveillance footage.

"Open a Senkaimon. I'll go deal with him now."

"My apologies, Captain Ailin."

Inaba, leaning on his cane, approached a computer and started typing.

"I don't want any complications, so I'd like you to travel to the past using the Kōtotsu. Eliminate Captain Aizen before he can expose us."

"The Kōtotsu will decompose anything with spiritual pressure. But it won't harm anything without it. Wait a moment. I'll create a device that can negate your spiritual pressure. Then, you can enter the Kōtotsu and travel to the past."

"A device to negate spiritual pressure?"

Ailin's Reigai scoffed.

"Are you looking down on me? What can a mere Kōtotsu do to me? Open a Senkaimon and send me to it. I'm eager to stretch my legs."

Inaba paused.

While he believed that traversing the Kōtotsu required a device to negate spiritual pressure, if this was Captain Ailin, it wasn't impossible.

After all, the "future" Ailin was already battling "Aizen" in the World of the Living.

It meant that Ailin had successfully passed through the Kōtotsu.

He wasted no time.

"Alright, Captain Aizen, I'll open a Senkaimon to the Kōtotsu."

As the Seireitei's foremost expert on the Dangai, Inaba's research on the dimensional void was unmatched.

He even monitored the Kōtotsu, the creatures that served as the Dangai's "cleaners."

He quickly located a Kōtotsu and opened a Senkaimon before Ailin's Reigai.

Ailin stepped through the portal, entering the pitch-black Dangai.

Before him, a one-eyed Kōtotsu was rapidly approaching, its movements accompanied by a deafening roar.

Just as the Kōtotsu was about to devour him, Ailin completely suppressed his spiritual pressure, erasing all traces of his presence.

Boom!

A flash of white light later, Ailin opened his eyes. He found himself in a vacuum-like environment.

Everything in this space was suspended in mid-air.

Ailin noticed something interesting.

Not far from him, a young woman with short, green hair lay motionless, covered by a gray cloth.

Further down, a young man with orange hair, clad in a black shihakushō, lay in a similar state.

Then, another young man with orange hair, wearing a white lab coat, appeared. He was collecting spiritual pressure using a glass test tube.

The Kōtotsu's nature was to decompose anything with spiritual pressure. This white-coated young man, collecting spiritual pressure within the Kōtotsu, was clearly disrupting its function.

A powerful vortex formed beside the young man.

The Kōtotsu was attempting to expel him.

The young man, realizing his predicament, quickly grabbed the black-clad young man and propelled them both towards the vortex.

But it wasn't just the two of them.

The vortex also pulled in the green-haired young woman.

However, she had been ejected at a different time, which might cause temporal discrepancies when they emerged from the Kōtotsu.

Ailin, having witnessed this scene, instantly understood its significance based on his original's memories.

The green-haired young woman was Nozomi Kujō, Ōko Yushima's other half.

When Ōko had submitted his "Soul Soldier Project" to the Seireitei, he had believed he would be lauded for his ingenuity. He had even envisioned himself being invited to join the Zero Division, just like Captain Hikifune.

However, to his dismay, the Central 46 had rejected his proposal.

They had deemed his research dangerous, believing it would destabilize the Seireitei. They had even attempted to apprehend him.

This was unacceptable to Ōko.

He had used his "Mod Soul" technology to modify his own soul and split it into two beings: Kageroza Inaba and Nozomi Kujō.

Inaba had inherited Ōko's memories and knowledge, while Nozomi had inherited his personality.

This way, Ōko had successfully evaded capture. Inaba, possessing Ōko's memories, had added his name to the list of researchers involved in the "Temporary Soul" project, effectively erasing his past.

After the "Temporary Soul" research group had disbanded, Inaba had begun studying the Dangai and, with his exceptional talent, had become the director of Dangai research.

Through his research on the Dangai and the Kōtotsu, he had created a device to negate spiritual pressure. He had then sent his other half, Nozomi, into the Kōtotsu, hiding her within the dimensional void.

He planned to complete his "Soul Soldier" research, create Reigai of the most powerful captains, and then fuse with Nozomi, becoming Ōko Yushima once more. He would then initiate his revolution, bringing change to the Seireitei.

The black-clad young man and the white-coated young man were the same person.

He was Ichigo Kurosaki, the protagonist of this world, born with the powers of a Shinigami, a Hollow, a Fullbringer, and a Quincy.

The scene Ailin had witnessed was Ichigo, having lost his spiritual pressure, entering the Kōtotsu under Urahara's guidance. He had successfully collected his scattered spiritual energy and had even pulled out his past self, who had been absorbed by the Kōtotsu.

Moreover, Ichigo's actions had inadvertently dragged Nozomi out of the Kōtotsu.

Since time didn't flow within the Kōtotsu, even though Nozomi had exited after Ichigo, she had arrived in the World of the Living before him.

Of course, since they had been ejected through the same vortex, the time difference wasn't significant.

Seeing these three emerge from the Kōtotsu, Ailin's Reigai knew that the future of the Bleach world hadn't changed drastically.

At least, Ichigo Kurosaki had been born and had become a Shinigami.

He had even used the "Final Getsuga Tenshō."

Of course, Ailin's Reigai could only guess this much based on what he had witnessed within the Kōtotsu.

He would have to experience the rest for himself!