The Curtain Rises  

After Kisuke Urahara became the 12th Division Captain, Ailin knew the prologue of the Soul Reapers was about to unfold.

Mayuri Kurotsuchi from the Nest of Maggots in the 2nd Division, was released by Urahara to serve as his lieutenant.

Moreover, to ensure Mayuri worked diligently for him, Urahara made a wager with him:

While Urahara was the 12th Division Captain, Mayuri would devote himself fully as his subordinate.

Once Urahara was no longer the 12th Division Captain, Mayuri would take full control of the division, free to research, invent or create anything without interference.

Thanks to the efforts of Urahara and Mayuri, in just a few short years Soul Society's technology underwent a massive reform.

Especially the Department of Research and Development - their bulky old machines were replaced with computers featuring displays. Monitoring stations with spiritual particle sensors were installed everywhere, able to display live video feeds far more conveniently than before.

Additionally, Urahara invented the "Spirit Messengers" with communication and scanning capabilities. The Soul Reapers stationed in the World of the Living cherished these devices, drastically reducing time spent searching for Hollows.

It seemed everything was progressing smoothly. However, beneath Soul Society's calm surface raged tumultuous undercurrents.

In recent years, even without actively monitoring, Ailin noticed that virtually all Hollows entering Soul Society or the World of the Living were merely small or mid-level ones.

There had been no sightings of Gillian-class or higher-level Menos Grandes.

After so long, to the new students of the Spiritual Arts Academy and freshly recruited Soul Reapers, Gillian-class Hollows had become mere "legends."

Some more knowledgeable but inexperienced Soul Reapers, upon learning of the existence of the Royal Guard's Zero Division, even speculated that Gillian Menos and above were mighty foes only the Zero Division could handle. They spread such rumors to impress naive young women.

Unexpectedly, these tales found a market.

Some captains had heard such gossip, but to them it was just laughable hearsay.

If even Gillian Hollows required the Zero Division's intervention, didn't that make the Thirteen Court Guard Squads seem too weak?

The Forest of Menos in Hueco Mundo teemed with hundreds of thousands of powerful Hollows. If only the Zero Division could handle them, how many members would it need?

More than all Thirteen Court Guard Squads combined?

One captain's shaking head and bitter smile became the most compelling "evidence" validating these rumors among new Academy graduates and recent Squad recruits as unquestioned "legends."

Generally speaking, without Gillian-class or higher Hollows appearing, Soul Reaper casualties should have been effectively contained.

Yet puzzlingly, while the Hollows entering the World of the Living and Rukongai had become weaker, Soul Reaper casualties only increased.

To the upper echelons, losses among ordinary or elite Soul Reapers hardly mattered.

Had Ailin not paid casual attention, he likely wouldn't have noticed how many perished over the years.

However, Ailin knew the Hogyoku Aizen possessed had finally been fully awakened!

...

Clang Clang Clang

That day, the urgent summons for captains echoed once more throughout Seireitei.

After informing Haruko, Ailin swiftly made his way to the 1st Division barracks.

Soon, the thirteen captains of the Thirteen Court Guard Squads assembled in the meeting hall, lining up in order.

"My, it feels like over a decade since we last heard that urgent summons. When I heard it today I almost thought the 1st had gotten the signal wrong," Shunsui Kyoraku mused, fanning himself lazily.

Standing beside him, Ailin remarked, "Haha, Captain Kyoraku, not receiving a captains' summons for so long is evidence of Seireitei's peace, isn't it? If Seireitei reached the point of needing captains' meetings every day, I suspect it would already be on the brink of destruction..."

"Indeed, tranquility has long prevailed... But maintaining that peace is the very purpose of our existence."

"Silence!"

Seeming to hear the exchange between Ailin and Kyoraku, Captain-Commander Yamamoto barked sternly, his cane striking the meeting hall floor heavily.

Thud!

"I have summoned you captains here today because the 12th Division detected residual spirit particles and Soul Reaper garments while monitoring Rukongai. Captain Urahara, brief everyone on your division's findings regarding this incident."

"Yes, Captain-Commander."

Urahara stepped forward from the line of captains. "Fellow captains, our Department of Research and Development has concluded the owners of those garments had their souls utterly consumed in an instant, leaving only clothes behind...

We suspect some abnormally powerful Hollow may have evaded Seireitei's surveillance to openly attack Rukongai residents and the Soul Reapers sent to defeat it. Furthermore, this Hollow has likely been present in Soul Society for quite some time.

Our in-depth investigation revealed Soul Reaper casualties have been rising steadily for the past thirty years...

Yet according to our monitoring data, neither Soul Society nor the World of the Living has detected any Gillian-class or higher Hollows during that same period. Such losses are highly abnormal without more dangerous Hollows appearing.

Indeed, Soul Reaper casualties should have decreased without stronger Hollow threats. Based on the number of deceased Soul Reapers and Rukongai residents, this Hollow's power may have surpassed Gillian level, reaching Adjuchas rank..."

"Now that you've heard Captain Urahara's briefing, are there any captains willing to investigate and eliminate this supposedly hidden Hollow?" After the Captain-Commander's query, the gathered captains fell silent.

If the Hollow's activities truly were confined to a certain area, those present would gladly hunt it down. Even an Adjuchas-level Hollow posed no real threat to this assembled force of captains.

However, the very existence of such a Hollow remained unconfirmed speculation. Accepting this mission meant personally searching for leads - who knew when they might finally locate the target?

What a hassle...

The captains either grinned wordlessly, closed their eyes feigning sleep, or outright pretended deafness.

Their unified stance - you don't volunteer, I won't either.

"Hmph!"

Seeing the captains' reluctance, Yamamoto let out a cold grunt of displeasure. Then he started calling names.

"Squad 3 Captain Rojuro Otoribashi, Squad 5 Captain Shinji Hirako, Squad 7 Captain Love Aikawa, Squad 9 Captain Kensei Muguruma."

"Yes, Captain-Commander."

Summoned by name, the four captains stepped forward into the hall's center.

"I will task you four with this investigation. However, considering this search may not suit your strengths, I have procured two powerful assistants for you."

As he spoke, Genryusai Shigekuni Yamamoto raised his voice slightly. "Enter."

No sooner had the Captain-Commander's words left his lips than the great doors opened, two figures striding into the meeting hall's bright light.

"Captain-Commander Yamamoto."

The man in front, sporting a neat goatee and stern expression, wore a purple "koken" robe signifying his exalted rank as a master of Kido sorcery. A gnarled staff in his right hand marked him as the Grand Kidō Chief.

Behind him followed an immensely obese man in crimson garb, outweighing even the greatest master in the neighbouring Fifth Division's Kido Corps.

Like the other captains, Ailin studied the imposing Grand Kidō Chief Tessai Tsukabishi intently.

Although this was the first time most had seen the leaders of the Kidō Corps, Ailin was quite familiar with Tessai's current dignified demeanor destined to give way to bumbling servitude after these events.

"These two are the current Grand Kidō Chief Tessai Tsukabishi and his assistant, Hachigen Ushōda," Yamamoto introduced them. "For this mission investigating the 'vanishing souls' in Soul Society, they will assist you in locating and eliminating the Hollow responsible for devouring them."

"Yes, Captain-Commander Yamamoto."

"Hold a moment..."

Just as Hirako and the others were about to depart, Squad 8 Captain Shunsui Kyoraku raised his hand.

"You may require intelligence support from my Division during this investigation. Allow my lieutenant, Lisa Yadomaru, to accompany and aid your efforts. With her informant contacts, we're bound to uncover this hidden Hollow's whereabouts sooner."

"Much appreciated, Captain Kyoraku." After thanking him, Hirako went with the other captains to the 1st Division's waiting room, summoning Squad 8's Lieutenant Lisa Yadomaru to join their search party for Rukongai.

In the interim, Squad 9's Lieutenant Kuna Mashiro and Squad 12's Lieutenant Mayuri Kurotsuchi insisted on participating as well. Left with no choice, Hirako allowed them to come along too.

Once the captains had all departed, Squad 5 Lieutenant Sosuke Aizen pushed his glasses up, his expression one of benevolent calm.

The fish had taken the bait.