Shinigami in the Ninja World (Re-upload)

The Ryoka caused chaos in the Seireitei, plunging the Shinigami into turmoil.

Despite their small numbers, the trouble they stirred was enough to instill fear.

Two captains had been defeated!

One of the Ryoka, a boy suspected to be a Quincy, had managed to defeat the 12th Division Captain, Mayuri Kurotsuchi. However, though he succeeded, he completely exhausted his strength and was easily captured by the 9th Division Captain. He was now imprisoned in the 4th Division barracks.

This event didn't surprise the Shinigami much.

After all, the 12th Division specialized in research and development, and Captain Kurotsuchi was not known for his combat prowess.

For a Ryoka to infiltrate the Soul Society, it was expected they'd possess abilities capable of contending with captains. Otherwise, why would they dare to intrude?

But the real issue wasn't just that two captains had been defeated—it was who the other defeated captain was.

The second captain to lose was the 11th Division Captain, Kenpachi Zaraki.

Unlike the 12th Division, the 11th Division was the "Combat Division." Their sole purpose was battle. Wherever there was a fight, they were expected to be there, and their captain was a master of combat.

In the Seireitei, captains typically specialized in specific roles. For example:

The 2nd Division Captain excelled in assassination and pursuit.

The 4th Division Captain was a master of healing.

Each captain had their area of expertise.

To most Shinigami, the strongest figure in the Seireitei was, without question, the Captain-Commander. But beneath him, there was ongoing debate about who came next.

Members of the 2nd Division believed their captain was second only to the Captain-Commander.

The same was said by members of the 6th, 8th, and 11th Divisions.

The 10th and 13th Divisions had unique circumstances, with one captain being too young to fully mature and the other perpetually ill and frail.

Still, regardless of personal bias, Kenpachi Zaraki was almost universally acknowledged as the second-strongest captain in the Seireitei.

And yet… he had lost.

What's more, it wasn't even a mutual defeat. The 11th Division's lieutenant returned with Kenpachi Zaraki's unconscious body, but the opponent was nowhere to be found on the battlefield.

What terrified the rank-and-file Shinigami even more was the identity of the person who had defeated Zaraki.

It was none other than the human boy Byakuya Kuchiki had recently fought—the one who had stolen Rukia's Shinigami powers and was subsequently stripped of those abilities by Byakuya.

How was this possible?

The Shinigami were baffled.

Even Shinigami lose spiritual energy after sustaining heavy injuries. For an ordinary human to endure such damage and keep fighting was unimaginable—his physical body was likely the only reason he survived.

But regaining spiritual energy was one thing…

How had he made such rapid progress in such a short time?

From being effortlessly defeated by Byakuya to overpowering Kenpachi Zaraki?

What about the future? Could his growth continue to the point where he could easily kill captains—or even rival the Captain-Commander himself?

…

As night fell, a relative calm returned to the Seireitei.

Most of the Ryoka had already been captured, except for the ringleader—the one who had defeated Kenpachi Zaraki.

That individual was still at large, disappearing without a trace.

It was speculated that, although he managed to defeat Zaraki, he likely sustained serious injuries and was now in hiding, recovering from the battle.

…

2nd Division Barracks

The moment Sasuke returned, several eager gazes turned toward him.

Soi Fon glanced at him shyly, unable to look directly for too long.

Marechiyo Ōmaeda, however, had no such reservations and openly stared at his captain.

"Captain, did you find the remaining Ryoka?"

Sasuke shook his head, answering curtly. "No. It seems they had prior knowledge about me. They possess some ability that continuously disrupts my tracking."

"Prior knowledge? Disruption?" Ōmaeda frowned, muttering in confusion. "I've never heard of them having that kind of power."

Sasuke shot him a sharp glance.

Ōmaeda immediately pointed to Sasuke's desk. "The abilities of the captured Ryoka have already been compiled and placed there for you."

After years of working together, they had developed an unspoken understanding. A single look from Sasuke was enough for Ōmaeda to know what his captain wanted.

Soi Fon stood to the side, hesitating as though she wanted to speak but didn't dare.

Sasuke walked to his desk, picked up the report, and began reading with a focused expression. Without looking up, he said a single word: "Speak."

"This is no simple matter!" Soi Fon took a deep breath.

Sasuke didn't bother to respond. To him, it was an unnecessary and obvious statement.

"I investigated the traces left by the Ryoka when they entered the Soul Society," Soi Fon continued, aware of Sasuke's impatience. Her voice grew louder and angrier with every word. "They used a Senkaimon!"

Sasuke glanced at her for the first time.

"The technology to use a Senkaimon requires prior authorization," Soi Fon explained, her frustration evident. "Of course, if it's the 12th Division, they could use it secretly without detection.

"So, this can only be done by someone from the 12th Division—or someone who once worked there."

"Today's battle already proved that Captain Mayuri Kurotsuchi has no connection to the Ryoka."

Even under desperate circumstances, it was clear that Kurotsuchi had fought sincerely. His injuries could be faked, but the Quincy boy, Uryū Ishida, had paid a genuine price, his spiritual particles leaking so rapidly it nearly frightened the 4th Division members treating him.

Sasuke raised an eyebrow, already suspecting what Soi Fon was leading toward.

Sure enough…

"This must be connected to that hatted man!" Soi Fon growled, spitting out the words with visible anger. "Only Kisuke Urahara could open a Senkaimon in the World of the Living!"

Sasuke flipped to the next page of the report.

"The Senkaimon isn't highly advanced technology. Any seated officer could access it."

"There are plenty of defectors from the 12th Division—Kisuke Urahara isn't the only one."

Soi Fon froze, stunned by the rebuttal.

"Anything else? Or is that all?" Sasuke asked while continuing to read.

Soi Fon nodded quickly. "Yes—there's also… a cat!"

"A cat?" Sasuke asked, not looking up.

"One of the 7th Division's members reported seeing a black cat alongside the Ryoka when they breached the Soul Society."

Sasuke paused his reading, speaking softly. "A black cat?"

A black cat wasn't inherently unusual, but in this case, it was far from ordinary. A black cat associated with an incursion into the Seireitei could only point to one individual: the former 2nd Division Captain, Yoruichi Shihōin, known for her ability to transform into a black cat.

"Captain! You know what this means!" Soi Fon slammed her hand on the desk, her face contorted with frustration. "We should have acted against her long ago! I don't understand why the Central 46 never approved it. Now, she's followed us into the Soul Society and even into the Seireitei—"

Sasuke raised his hand, cutting her off. "If you want to investigate, then do so."

"Lead the Onmitsukidō."

Soi Fon's eyes lit up with excitement, and she responded enthusiastically. "Yes, sir! I'll definitely capture that arrogant woman!"

She turned and left the room quickly, her eagerness palpable.

Once the door shut, Ōmaeda hesitated before speaking. "Captain, letting Soi Fon handle this… is it really a good idea?"

Sasuke didn't even look up. "Is there a problem?"

Ōmaeda shook his head, suppressing a sigh. The Seireitei was already in chaos, and now Soi Fon was being sent after Yoruichi Shihōin.

Everyone in the 2nd Division knew about the complicated history between Soi Fon and Yoruichi. Sending her after Yoruichi would only stir up even more trouble.

But then again…

The captain was far more intelligent than him and undoubtedly aware of the consequences. If Sasuke believed it wasn't an issue, then Ōmaeda's concerns were likely unnecessary.

With that thought, Ōmaeda shrugged and decided to remain quiet.

…

Half an hour later…

Sasuke put down the report and waved to Ōmaeda. "You can leave now."

Ōmaeda blinked in surprise, then stretched and yawned. "Finally! I've been wanting to rest for ages. You should've promoted Soi Fon to lieutenant ages ago, Captain."

Sasuke waved him off without responding.

Ōmaeda lazily shuffled his upper body but walked briskly, his wide strides taking him out of the room without a backward glance.

As soon as the door shut behind him, Sasuke looked up. "You can come down now."

A shadow leaped from the rafters, landing gracefully on the desk. Stretching leisurely, it revealed itself to be a black cat with gleaming golden eyes.

It was none other than Yoruichi Shihōin, the very person Soi Fon had just been assigned to find.

Ōmaeda's footsteps faded in the distance.

"Ōmaeda is as sharp as ever," Yoruichi remarked with amusement, her voice smooth yet teasing. "But you're even harsher, sending Soi Fon after me."

"Her Zanpakutō is quite dangerous, you know."

Sasuke ignored her greeting, tossing the report onto the desk. "What's going on?"

"I've read the Ryoka files. None of them have abilities that could deceive me."

Uryū Ishida was a Quincy, and the Shiba family's involvement was straightforward. Of the remaining two humans:

Orihime Inoue, whose abilities were versatile—capable of healing and offense. While impressive, her spiritual pressure was weak. Her skills didn't include deception or concealment.

Yasutora Sado, whose power was purely offensive.

"Deception, huh?" Yoruichi flicked her tail and leaped onto the chair, sitting comfortably.

"What's going on?" Sasuke pressed, his expression stern. "I searched all day and couldn't find you. Someone is interfering with me."

"If it's the remaining Ryoka…"

Yoruichi shook her head, her expression grave. "No, it's not Ichigo. His abilities aren't in the realm of spiritual deception."

"And he's too much of an idiot to try something like that."

"It's someone else."

Sasuke frowned, his confusion deepening.

If it wasn't Yoruichi's group, then who was helping to obstruct his search?

"I don't know either," Yoruichi admitted, curling her tail. "But before I came here, Kisuke Urahara told me to pass along a message if anything unusual happened."

Sasuke sat up straighter.

"One hundred and ten years ago, the tool that caused Shinji Hirako and the others to undergo Hollowfication was called the Hōgyoku. It's a special artifact created using fragments of the Soul King's power."

"That artifact possesses immense strength," Yoruichi explained, her voice serious. "Someone in the Seireitei has their sights set on it."

"Previously, Kisuke hid the Hōgyoku inside Rukia's body."

Sasuke's expression sharpened. "So the death sentence—was it an attempt to kill her and extract the Hōgyoku from her body?"

Yoruichi nodded.

Sasuke's brows furrowed. "The Kuchiki family? Or the Tsunayashiro family?"

The first two names that came to Sasuke's mind were Kuchiki and Tsunayashiro.

The Kuchiki family's reaction had been highly unusual. Others might not understand the nuances, but as the captain of the 2nd Division, Sasuke knew the truth. Rukia was not some lucky girl who had randomly caught Byakuya Kuchiki's favor.

She was the younger sister of the late Kuchiki matriarch, a woman from Rukongai whose presence had caused a stir in the Seireitei. Rukia was her dying wish—the only thing left of her.

Given Byakuya's love for his wife—a love strong enough to defy opposition and marry her—it was hard to believe he would simply allow her sister to be executed unless there were circumstances Sasuke didn't yet understand.

As for the Tsunayashiro family, Sasuke's suspicion was simple. In all his years as the 2nd Division captain, any case requiring seated officers or higher to investigate was almost always tied to the Tsunayashiro family in some way.

Once the most prominent of the Five Great Noble Houses, the Tsunayashiros were notorious troublemakers. They rarely involved themselves in anything noble or honorable, but when something shady occurred, their fingerprints were often there.

Whenever chaos erupted, assuming their involvement was rarely a mistake.

"Neither," the black cat said, shaking her head swiftly.

Sasuke's tone turned sharper. "It seems you already know who's responsible."

"Indeed," Yoruichi replied with a sly grin, her golden eyes gleaming as she watched Sasuke's expression closely. She spoke the name slowly, almost savoring the moment: "Sōsuke Aizen."

"Well? Didn't see that coming, did you?"

She seemed eager to see a reaction, but the black-haired young man remained composed, his cold demeanor unchanged.

"Is that so? A bit unexpected," Sasuke said calmly.

Yoruichi scoffed, flicking her tail. "You're getting more boring by the day, Sasuke. Not even that man surprises you?"

Sasuke's calm demeanor betrayed none of his thoughts. He understood why Yoruichi was trying to provoke him. Captain Sōsuke Aizen of the 5th Division was widely regarded as an exemplary Shinigami, with a spotless reputation. Even the 2nd Division had no dirt on him.

But Sasuke had little interest in the politics of the Soul Society or its captains. His interactions with Aizen were superficial at best.

"What kind of ability does he have?" Sasuke asked, tilting his head. His sharp gaze met Yoruichi's. "What kind of power could force someone like Kisuke Urahara—or you, the Shihōin family's leader—to flee the Soul Society and hide in the World of the Living?"

And more than that…

What kind of power could manipulate the Central 46 Chambers into sentencing Rukia to death?

Yoruichi's expression turned serious. "His Zanpakutō."

"It's not the water-type he pretends it to be. Its true power lies in illusion."

Sasuke's eyes narrowed, his expression hardening instantly. Illusion? This directly challenged the Sharingan's dominance.

"The Seireitei's analysis suggests that his Zanpakutō can control senses—manipulating what others perceive at will," Yoruichi continued, her tone bored but her words grave. "Everything people see is what he wants them to see. That's why things have escalated this far."

She sighed. "If only we'd known about his ability earlier, we could've prepared for it. Unfortunately…"

If they had been forewarned, Kisuke Urahara wouldn't have been forced to flee the Seireitei in disgrace.

Sasuke mulled over her words.

So that's how it was. Aizen's Zanpakutō concealed his misdeeds and crafted his perfect image.

"Why didn't you tell me this before?" Sasuke asked, his cold eyes locking onto Yoruichi's. His tone was sharp, bordering on accusatory, with no hint of restraint.

Yoruichi hesitated before letting out a nervous laugh, waving her paw dismissively. "You were too young back then! Besides, everything was such a mess. We were too busy helping you become a captain."

"We just… forgot, I guess. Haha! If we'd told you back then, maybe things wouldn't be so chaotic now."

Her explanation reeked of insincerity.

Clearly, this wasn't the truth.

While Yoruichi might be indifferent, Kisuke Urahara had likely chosen to withhold this information deliberately.

Sasuke didn't press further.

The real reason was as he suspected—Kisuke didn't want him to know.

The reason was simple.

The Hōgyoku was synonymous with immense power. And while Sasuke had frequent interactions with Yoruichi and Kisuke, his obsessive nature and the ominous power of his Sharingan left a poor impression on Urahara.

Stubborn individuals like Sasuke were the most susceptible to temptation.

Kisuke feared that if Sasuke learned about the Hōgyoku and its potential, he might act in unpredictable and uncontrollable ways.

But the situation had changed.

Before Yoruichi returned to the Soul Society, Kisuke had warned her to closely monitor Sasuke.

If Sasuke handled things too smoothly—whether it was capturing Ichigo Kurosaki or avoiding any meaningful involvement—it would mean only one thing: Sasuke had sided with Aizen.

If Sasuke's actions appeared constrained or hindered, it would prove he wasn't aligned with Aizen.

Yoruichi could understand if Sasuke chose to slack off, but success? That would be suspicious.

Kisuke explained that Sasuke's path to capturing Ichigo would never be easy. Aizen was undoubtedly interested in Ichigo and would ensure he didn't fall into the wrong hands.

For Aizen, the worst-case scenario was Ichigo ending up with a capable outsider like Sasuke.

Only after seeing Sasuke struggle against these obstacles could Yoruichi reveal the truth.

If Sasuke's actions were suspiciously smooth, Yoruichi was not to make contact.

Sasuke broke the silence. "What do you need me to do?" He waved off further questions, his voice sharp. "Your goal now is just to clear your name, isn't it?"

Yoruichi shook her head. "That doesn't matter anymore."

"The real issue is what Aizen plans to do with the Hōgyoku. Kisuke has a terrifying theory. If he's right…" she paused, her golden eyes narrowing.

"All three worlds are in danger."

Sasuke's expression didn't change.

"Three worlds in danger" was a phrase that held no particular weight for him.

Yoruichi continued softly, "Kisuke believes your Sharingan's insight could be a powerful counter to Aizen."

"Because the illusions we see are manipulated by him, not born from within us. If he encounters something unfamiliar or outside his expectations, his illusions might falter."

"That's your chance to catch him. Use those eyes of yours wisely."

Yoruichi paused, flicking her tail. From somewhere, she produced a small vial of liquid and tossed it to Sasuke. "Kisuke made this for you. It's a special eye solution."

"It's designed to restore normal vision for nearsightedness. We're not sure if it'll work on your Sharingan's visual anomalies, but it might help a little."

Sasuke caught the vial, hesitating for a moment.

Yoruichi bristled immediately. "It's clean! What are you thinking, you brat?"

"You've gotten so much less adorable over the years."

Sasuke placed the vial on the desk. "So there's no rush to expose Aizen?"

"Not until there's enough evidence," Yoruichi replied. "We can't alert him too soon."

Sasuke lowered his gaze. Out of Yoruichi's sight, his Sharingan activated, its three tomoe spinning slowly.

"So that's it," he muttered to himself.

Aizen's illusions had been so flawless they had even eluded the Sharingan… until now. The strange distortions Sasuke had sensed earlier in the day suddenly made sense.

…

The Next Day

Sasuke awoke and began briefing his division members, preparing to continue yesterday's operations. He wanted to see if Aizen would continue interfering and hoped to uncover some clues in the process.

But before he could leave, a shocking piece of news thundered through the Seireitei.

Captain Sōsuke Aizen of the 5th Division was dead!

Assassinated—killed with a single strike.

At the 4th Division barracks, in the mortuary, Captain Retsu Unohana stood over the body, her brows furrowed in thought.

"Captain Uchiha wants to see Captain Aizen's body," Vice-Captain Isane Kotetsu reported quietly, stepping closer.

Unohana's eyes flashed with recognition, recalling the haunting crimson glow of Sasuke's Sharingan. She nodded. "Bring him in."

Her expression remained nearly unchanged, as serene as ever, though her faint, habitual smile was conspicuously absent.

"Captain Uchiha, to what do we owe the honor?" Unohana greeted him with a polite smile as Sasuke entered.

In the entire Seireitei, very few individuals were capable of killing someone like Aizen, who had served as a captain for over a century.

And among those individuals, the one with both the means and temperament to carry out such an assassination… was none other than Sasuke Uchiha.

"I'm here to examine the body," Sasuke said curtly, moving to the bedside and gripping his sword.

Activating his Sharingan, Sasuke began his inspection, scanning the corpse from head to toe.

He expected Aizen's body to reveal some flaw. After all, the "self" one perceives through their own eyes and the way others see them are often different, and familiarity tends to blind people to subtle inconsistencies.

But…

The body before him was indistinguishable from the Aizen he knew.

Sasuke's brow furrowed.

Even with the Sharingan, which could capture the smallest, imperceptible details invisible to others, there was no obvious evidence. And without proof, these minute discrepancies could never serve as legitimate evidence.

"Captain Uchiha, did you find anything?" Unohana asked as she stepped closer.

Sasuke turned to meet her gaze.

"Did you notice something, Captain Unohana?" he countered, locking eyes with her.

Unohana shook her head. "I simply feel… something is off. But I can't put it into words."

"Is that so?" Sasuke replied softly.

If even Unohana, the Soul Society's greatest healer and most experienced observer of death, could only describe her unease as a vague "offness," then Aizen's deception was truly extraordinary.

Before they could delve further, a surge of spiritual energy from a Kidō alert swept across the Seireitei, summoning them both to the 1st Division barracks.

It had been over a century since the Gotei 13 last lost a captain.

This event was of grave importance.

Even Kenpachi Zaraki's recent defeat paled in comparison to the ramifications of this incident.

As Sasuke and Unohana made their way toward the 1st Division barracks, an angry shout echoed through the air.

"Found you, Sasuke Uchiha!"

Sasuke turned his head to see a young woman with black hair tied in a loose braid, dressed in standard Shinigami attire. A lieutenant's badge adorned her arm, and her face was flushed with rage and grief.

It was Momo Hinamori, Vice-Captain of the 5th Division.

"You're the one who killed Captain Aizen!" she screamed, tears streaming down her face. "I'll avenge him!"

Without hesitation, she drew her Zanpakutō.

"Snap, Tobiume!"

Her blade transformed, extending like the branches of a tree before launching a massive fireball directly at Sasuke.

Sasuke didn't move. He simply gripped his sword, the Sharingan spinning in his eyes.

To Hinamori, it looked as though her attack had hit perfectly, her fireball striking Sasuke dead-on. She clenched her fists, relief and triumph momentarily washing over her. Finally, she had avenged—

The word "revenge" hadn't even fully formed in her mind before a sharp kick landed on her waist, sending her sprawling to the ground.

A heavy foot pressed against her face, forcing her to look up.

Standing over her was the very person she believed she had just attacked—Captain Sasuke Uchiha.

His uniform was spotless, untouched by any explosion or scorch marks.

"I killed Aizen?" Sasuke's voice was icy, his foot applying slightly more pressure. "What made you think that?"

"What's your reasoning?"

Hinamori gritted her teeth, spitting out her response. "Captain Aizen himself said so! He wrote it in his farewell note! He discovered your grand conspiracy. Going after the Shihōin family was only the first step. You planned to use Rukia to target the Kuchiki family. But Captain Aizen uncovered your schemes…"

"He foresaw his own murder at your hands!"