(T/N: Hello everyone!! Sorry about yesterday, I will make it up for you, tomorrow. Today like usual it's three chapters! Tomorrow there will be 6 chapters!)
After Nanatsuki resolved one problem, another soon followed. Using his Shikai in the Noble District released a burst of captain-class Reiatsu so intense that it startled the district's guards.
Once he sealed his Zanpakutō again, Nanatsuki saw the guards closing in.
The Mizutani estate was strewn with artificial corpses, and the scene was serious enough that the guards had to investigate.
Despite trying to maintain composure, the guards couldn't help but use honorifics as they questioned him:
"Master Katori, may we ask what you're doing?"
"Don't be alarmed," Nanatsuki said gently, sheathing his blade. "These are Reishi Shells, not Shinigami."
"Reishi Shells? Those artificially-made spirit bodies…?"
"I heard that kind of Reishi manipulation is a forbidden technique..."
"Right. Third, Eighth, and Thirteenth Divisions are currently combing through Rukongai because of them..."
"But we can't verify what's true or not..."
"Master Katori, please wait here for a moment—we've already informed Captain Kuchiki!"
The guards exchanged glances. They had heard of Reishi Shells but couldn't determine whether Nanatsuki was telling the truth.
As members of the Sixth Division, these guards wanted to wait for Kuchiki Ginrei to arrive and assess the situation.
"You could also notify the Twelfth Division. Have them send a team to analyze the remains," Nanatsuki said in a calm voice.
Not all of the Mizutani family's guards lying on the ground were necessarily Reishi Shells, but considering their collusion with Miyamoto Tetsuya in producing artificial Shinigami and Academy trainees, Nanatsuki didn't regret eliminating them.
Just then, Nanatsuki's Denreishinki beeped.
He opened it and heard the voice of Shihoin Yoruichi:
"Master, are you still at the Academy? I've discovered something important!"
"Important?" Nanatsuki raised a brow. He recalled she had been stationed at the academy gate, tracking a newborn Reishi Shell.
"I've found a few issues myself, but... I ran into a little trouble."
"What happened?" Yoruichi asked immediately.
"I cut some people down at the Mizutani estate," Nanatsuki replied casually.
"I found a number of Reishi Shells here. But the Noble District guards didn't know much about them, and it caused some confusion."
"I'll head there right away!" Yoruichi said urgently.
After ending the call, Nanatsuki stayed put to await Yoruichi and Kuchiki Ginrei.
Though Yoruichi rushed over with all haste, Ginrei and the Twelfth Division arrived first.
Ginrei couldn't identify Reishi Shells by sight. Upon arriving, he immediately requested the presence of Hikifune Kirio to examine the remains.
"They are indeed Reishi Shells," Kirio confirmed after dissecting several of the corpses.
"The Spiritual Pressure Core, soul-chain, and soul-sleep don't match the spiritual body's strength. These are clearly artificially enhanced. It aligns with what we've seen from prior captures."
"But their decomposition rate has slowed dramatically. Miyamoto Tetsuya's Reishi Shell technique has clearly advanced," she added, instructing her subordinates to transport the bodies.
In the past, Reishi Shells created with early techniques would quickly disintegrate into Reishi upon death.
But these had nearly the same stability as regular souls and could persist for some time after death.
Kirio's assessment visibly relieved Ginrei and the Sixth Division officers.
After all, Katori Nanatsuki wasn't just a respected guest sword instructor for the Kuchiki family—Ginrei had even considered having him take young Byakuya as a disciple when the boy came of age. He wanted no conflict with Nanatsuki.
"It was our failure that so many Reishi Shells infiltrated the Noble District," Ginrei said sincerely.
"We owe it to Katori-dono for exposing them before they could pose a threat to the district—or even the Seireitei."
"Indeed," Kirio smiled.
"A few years ago, it was also Katori-dono who uncovered a Reishi Shell infiltrating my lab. Had we not caught it early, it would've accessed sensitive research."
"Mizutani Shingo and his Reishi Shell granddaughter might know where Miyamoto Tetsuya is hiding," Nanatsuki added.
Nanatsuki had spared Shingo's life using Kaido after defeating him, though his own Shikai had faded by then and left him gravely injured.
"He's unconscious for now, but we can start by disabling the anti-interrogation technique in his Reishi Shell's brain," Kirio nodded.
"Who would've thought the Mizutani family was colluding with Miyamoto Tetsuya... If not for Katori-dono's intervention, we might never have discovered this."
Years ago, after a mole incident in the Twelfth Division, the Seireitei initiated a screening program—but it didn't include the Noble District.
The Central 46 had denied Kirio's request to collect the nobles' Reishi data.
Had it been approved, she wouldn't have needed to dissect bodies to verify their nature.
"Now that this has happened, will Central 46 finally allow data collection?" Kirio glanced meaningfully at Ginrei.
"This was indeed a failure of both the Sixth Division and myself," Ginrei frowned.
"You're not to blame, Captain Kuchiki," Kirio said.
"Reishi Shells are difficult to detect. Without instruments, only dissection can confirm their identity. Still, if we want to prevent more incidents, we'll need approval to collect data."
"I'll persuade Central 46," Ginrei agreed.
At that moment, Shihoin Yoruichi arrived.
Seeing that the atmosphere wasn't tense, she exhaled in relief.
She had rushed here at full speed, exhausting her stamina and Reiatsu.
"You're alright, Master?" she asked, catching her breath.
She had feared a conflict between her master and the guards, which would've been messy.
But in her urgency, she'd underestimated the influence Nanatsuki held—neither the guards nor Ginrei would act rashly without clarity.
"I'm fine. Lady Kirio and Captain Ginrei judged the situation fairly," Nanatsuki said, warmth filling his heart as he noticed the sweat on Yoruichi's brow.
"Your disciple really cares for you," Kirio teased.
"She's dripping with sweat..." Nanatsuki chuckled and pulled a towel from his Reishi Pocket, gently wiping Yoruichi's forehead.
"Dry off first. So, what was this important discovery?"
Yoruichi took the towel from him, but when she noticed Kirio and Ginrei watching their interaction, her tanned cheeks reddened slightly.
Feigning ignorance of their gazes, she reported,
"We tracked a new Reishi Shell to the Suzuki Merchant Guild. It's likely a noble-owned business—there may be more collusion."
"The Suzuki Guild?" Ginrei thought for a moment.
"It's a Mizutani property. Mizutani Shingo's son-in-law is the guildmaster."
As head of the nobles' division, Ginrei dealt often with noble families and knew their business dealings well.
"So this intel's... not very helpful anymore." Yoruichi blinked.
"I thought I found a lead, but you've already caught the mastermind."
"Still useful," Nanatsuki said, patting her head.
"If the guildmaster had contact with Reishi Shells, he likely knows a lot. We can compare his testimony to Shingo's."
Since the Gotei 13 lacked a reliable truth serum, interrogations depended on the Detention Corps' methods.
Having multiple suspects helped verify information with higher accuracy.
"Then I'm glad it helps!" Yoruichi couldn't help but nuzzle his hand like a cat.
Ever since she mastered her feline transformation, she'd picked up some catlike habits—like rubbing her head against a hand after being petted.
"I'll head back now! I have to check if my team brought in the rest!" she said, suddenly aware of Kirio and Ginrei's amused expressions and feeling too embarrassed to linger.
Though bold in nature, she still showed a hint of inexperience in front of elders.
She vanished in a blur, retracing her path.
Ginrei, watching her leave, silently mused:'Is Katori Nanatsuki going to be the Shihoin clan's son-in-law...?'
If so, the Shihoin would gain not one but two captain-level pillars in the future.
Nanatsuki then assisted Kirio with the cranial procedure to disable the Reishi-based memory lock in the Shell's brain.
Both Mizutani Shingo and the adjusted Reishi Shell were handed to the Detention Corps for interrogation.
Two days later, when Yoruichi visited the dojo again, she brought a report from the interrogations.
"Miyamoto Tetsuya has a lab in the World of the Living?" Nanatsuki stroked his chin.
Surprising, but it made sense.
Based on what they knew, the Sound of Hell that belonged to Saitō Furaofushi was likely now in Miyamoto Tetsuya's hands.
It was also probable that Tetsuya had been influenced by the Will of Hell.
When Nanatsuki had created the Sound of Hell, Saitō had warned him: Frequent use of the technique, which received transmissions from Hell, risked mental erosion by its influence.
Tetsuya might already be under its control.
The Sound of Hell operated using Hell Reishi, and the memory-lock spells in the Reishi Shells' brains were constructed from the same substance.
And the only way to obtain Hell Reishi… was to gather it when the Gate of Hell opened.
Thus, building a lab in the World of the Living would be most convenient.
Using sinners as sacrifices, one could open the gate in the living world—while also minimizing the risk of discovery by the Gotei 13.
Shinigami stationed in the World of the Living were far easier to evade than those in the Soul Society.
"The mission to investigate Tetsuya's lab has been given to the Onmitsukidō," Yoruichi said.
"Would you come with me, Master?"
Nanatsuki nodded. "Sure. I just need to grab something."
"Then I'll gather my team and meet you soon!" Yoruichi left to assemble her forces.
Nanatsuki made his way to the lab.
There, he found Aizen Sōsuke recording data.
"You're just in time, Master," Aizen said, pausing his notes.
"Specimen #2 is growing rapidly!"
Nanatsuki approached the tank. Floating in the blue nutrient solution was a Hollow Reishi Shell.
After their trip to Hueco Mundo, Aizen had collected the sand necessary for Fungal Hollows to grow—
and quickly cultured a batch.
Using these as material, he created catalysts that accelerated Reishi Shell growth.
"Not bad," Nanatsuki nodded.
"The Reiatsu levels are already nearing those of a typical Hollow. I didn't expect them to grow faster than Shinigami Reishi Shells. At this rate, we'll reach Gillian-class specimens soon."
"Yes. I estimate we'll have viable test subjects for the Shinigami-Hollow transformation trials within a year," Aizen said, visibly excited.
"Progressing this fast is thanks to our prior groundwork."
"There's another reason too," Nanatsuki said, eyes narrowing as he stared into the tank.
"Hollow Reishi Shells have an endless supply of 'fodder' to devour and grow."
Aizen's catalyst had used this very principle—Hollows evolve by devouring other Hollows.
"True... Shinigami Reishi Shells can't grow that way."
Yet a different thought stirred in Aizen's mind—'Can't they?'
Neither he nor his teacher had ever tried feeding Reishi from one Shinigami Shell to another.
"Keep monitoring and documenting their growth. If any reach the Menos Grande level, we'll have made a major breakthrough," Nanatsuki said.
"I'm here to collect a batch of Reishi Shell inhibitors."
According to intel from the Mizutani estate, Miyamoto's lab likely had Reishi Shell guards.