Creating a Concentrated Spirit Zone required enormous chakra—and Yoru had already planned for that.
Initially, he intended to use a Tailed Beast as the energy source. After all, their chakra is nearly limitless and regenerates quickly. Kirigakure happened to house both the Three-Tails and the Six-Tails.
But each Tailed Beast cost 500,000 mission points—a temptation too great to ignore. Ultimately, Yoru gave up the idea in favor of a more expendable, cost-free solution: Edo Tensei.
Yes—the forbidden technique created by Senju Tobirama, infamous for its soul manipulation and role in the Fourth Great Ninja War.
Those revived by Edo Tensei possess infinite chakra, undying bodies, and absolute obedience to the summoner—ideal for powering chakra machinery.
After proposing the idea, Yoru discussed it with Hiromi and her team. They confirmed it was workable.
Though Edo Tensei grants limitless chakra, the output isn't as high as a Tailed Beast's, and the reanimated bodies only last 24 hours. Once time's up, the technique must be recast.
While slightly inconvenient, Yoru didn't mind. Apart from consuming White Zetsu cells, it was effectively free labor. He couldn't ask for more.
Hiromi summoned four Zetsu-based bodies and loaded them into sealed tanks filled with tissue. She then formed hand seals.
"Reanimation Jutsu!"
Though lacking consciousness, the Zetsu clones sensed impending danger and thrashed instinctively. In the next moment, chakra surged through their bodies, wrapping them in Mist ANBU attire.
Hiromi inserted talisman-infused kunai and activated the seal.
A hint of confusion lingered in the four individuals' eyes, but they quickly regained their clarity.
"Is it our turn to work again?"
"Lucky us. No fatigue, no boredom!"
"Just 25 more days—let's finish strong!"
"Lady Hiromi, you promised us revival after a full month's work. Don't break your word!"
They sounded like experienced workers rather than undead shinobi.
"Relax," Hiromi smiled. "The Fourth Mizukage is right here. Even if I tried to cheat, he wouldn't let me."
The ANBU looked up and bowed respectfully toward Yoru, who stood in his formal robes.
"Lord Fourth—an honor!"
"Please have Hiromi call me up more! I still have 25 days left!"
"Me too! I'm available!"
Yoru gave a faint sigh.
"As Mizukage, I should've revived you first. But this is for the village's future. Thank you for enduring it."
"It's our duty!" one said.
"We're Kirigakure shinobi—serving the village is an honor. And you're giving us a second chance. We're grateful, not burdened."
Indeed, if not for Yoru, they would've perished to Kushina's Tailed Beast Bomb, their souls trapped in the Pure Land. What they'd been given now was no less than salvation.
An A-rank mission might pay tens of thousands of ryō and take weeks, often risking death. But now, for a single month of chakra output, they could earn full resurrection.
"Alright," Hiromi clapped her hands. "Once you've met your quota, Lord Yoru will keep his promise. Until then, it's business as usual. I'll handle control—since this is a 24-hour task, you don't even need to stay conscious."
"Understood, Lady Hiromi!"
With a seal, their bodies stiffened. Like puppets, they moved to the console and began transferring chakra.
"Thank you for the hard work, Hiromi."
Yoru gently ruffled her red hair.
She had overseen soul experiments for months. Without her Uzumaki bloodline's stamina, she might've collapsed from sheer overwork.
She leaned into his hand like a content kitten.
"I'm fine, Lord Yoru. Serving you gives me strength. Honestly… if you stood behind me with a little whip, I'd be even more motivated…"
Her face flushed pink with excitement at the fantasy.
Yoru, used to her eccentric nature, pinched her cheek in exasperation. As they walked, he noted:
"Now that the chakra tower is running, Kirigakure is gradually becoming a Concentrated Spirit Zone. Shinigami can now absorb Reishi within Kirigakure to restore their Reiryoku and enhance it."
"Once I find a better chakra source—or improve Edo Tensei—you'll have less burden. But for now, I still need your help."
"Of course, Lord Yoru. It's just a jutsu…"
"Fourth Mizukage."
Suddenly, Yagura appeared beside them, clad in a white captain's haori.
"There's a situation."
Yoru's brow furrowed—he'd sensed it too. Without another word, he and Himeko vanished.
They reappeared in a clearing. Several Shinigami were present—including captains—all watching a single figure.
A massive, grotesque creature loomed. Its body was black and draped in something like a witch's robe. Its face bore a long-nosed clown mask, and in the center of its chest was a hollow hole.
"A Hollow…" Yoru said, narrowing his eyes.
"Looks like you've created something… significant."
As the origin of all Shinigami power in this world, Yoru could feel its spiritual signature clearly. This creature bore Shinigami power—but not from him.
"What happened?" he asked.
"We're not sure," said Hōzuki Mangetsu. "Shisui released several souls. Then something changed. They started fighting—devouring each other. And then this appeared."
"No clear mind—only instinct," Shisui added. "It's like a beast. Reminds me of that thing—but without the intelligence."
Yoru knew exactly what he meant—Satori.
"You think it was caused by the Box of Ultimate Bliss?"
"Seems likely. All other releases were normal—this was the only time the box was nearby," Shisui replied.
Yoru glanced toward the eerie, still Box of Ultimate Bliss. His mind quickly pieced together the scene:
After Shisui released the souls from his Rinnegan, those souls were anchored within Kirigakure by the influence of the Concentrated Spirit Zone. However, he hadn't noticed the presence of the Box of Ultimate Bliss during the release.
As a result, while those souls remained bound to the physical world, they came into contact with the Box of Ultimate Bliss, which activated their latent self-power.
It was well-known—especially to Yoru—that intense emotional stimuli could awaken the spiritual force hidden deep within a soul. And the Box of Ultimate Bliss just so happened to trigger a person's deepest fears.
Thus, under the box's influence, and tormented by endless fear, resentment, sorrow, and pain, those souls succumbed to madness. Then, under the passive influence of Yoru's Shinigami power, which permeated the entire village, they began to undergo a subtle transformation.
They became Hollows.
Driven by instinct, they devoured one another. In time, their chaotic consumption gave birth to the Gillian-class Hollow now before them.
"No wonder the system classified it as a special item…"
Yoru now understood. The Box of Ultimate Bliss was a key—the perfect trigger for Hollow creation.
Hollows weren't useless. If properly refined, they could rival high-level Shinigami. Even better? They cost far less to produce.
Creating a true Shinigami required a zanpakutō—or at least a substitute for Asauchi. Without that, mass production was impossible.
But Hollows? They needed only fallen souls and the right pressure.
"We might finally have a true undead army," Yoru murmured.
He turned back toward the Gillian, currently bound by Bakudō. The creature snarled at him—but something deep in its instincts recoiled. It didn't roar, it shrieked.
"In the Soul Society, Hollows can be purified—reborn as new souls."
"So in this world…"
He drew Hyorinmaru from his waist.
"You may be valuable for research—but as the first Hollow in this world, I'll give you the honor of being the test case for reincarnation."
In this world, there was no natural cycle of rebirth. Once someone died, their soul remained in the Pure Land until it dissolved.
Yoru wasn't sure if that rule was created by the Sage of Six Paths—or if the Pure Land was like the Bleach world's Hell.
But if purification worked—if a Hollow could be reborn—it would revolutionize the soul cycle.
Yoru is thinking that if he manages to restore reincarnation in the world (which currently lacks it), then in a Chinese xianxia context, he'd be like Houtu, the goddess who governs reincarnation.
He pierced the Gillian's head. Hyorinmaru's blade shattered its mask, and cracks spread across its massive form.
Moments later, a confused human soul emerged from its remains.
Yoru carried the soul beyond the edge of Kirigakure, out of the chakra tower's range.
But instantly, a strong force pulled the soul away—into the Pure Land.
"So... it doesn't work…"
Yoru frowned deeply.
Even a purified soul—free of Hollow corruption—couldn't reincarnate naturally. It was still dragged back to the Pure Land.
He considered investigating—but wasn't ready to challenge the Sage of Six Paths.
Yoru didn't lack a way to enter the Pure Land. Just the Rinnegan in Shisui's eye sockets alone was enough for him to sense the power of the Pure Land.
He returned to the clearing.
The Shinigami present all looked confused, not understanding what had happened.
Yoru waved them off.
"Just a small experiment. Nothing serious."
He continued:
"I know you're very curious about what that monster was. Simply put, it's a creature born from malicious fallen souls, twisted by Shinigami power, and ultimately created through mutual slaughter and devouring."
"I call it…"
"A Hollow."