Isshin Shiba’s Demise?  

"Hahaha, Captain Kyōraku, what are you talking about?"

Rangiku Matsumoto's brow beaded with sweat as she hurriedly denied Kyōraku's teasing remark.

"Hmph!"

Toshiro Hitsugaya's cold grunt made Kyōraku realize his mistake. Had he accidentally revealed Rangiku's complaints about her boss to her boss?

"Apologies, Matsumoto."

"So, I've been exploiting you all this time!"

"Hahaha, Vice-Captain Hitsugaya, don't listen to Captain Kyōraku. You know me better than that."

Rangiku put on a pitiful expression, trying to appease Toshiro with her usual charm. Sadly, while that tactic might work on adults, it was ineffective against Toshiro Hitsugaya.

"Hmph, we'll settle this later."

After reprimanding Rangiku, Toshiro approached Kyōraku.

"Captain Kyōraku, I have a few questions for you."

Toshiro was quite respectful towards his seniors, especially Kyōraku.

"Oh? Ask away, Vice-Captain Hitsugaya. I won't hide anything from you."

"Thank you."

Toshiro proceeded to explain the situation regarding Isshin Shiba's disappearance.

"Captain Kyōraku, you have extensive experience dealing with Hollows. Moreover, you were part of the investigation team the last time a Hollow appeared in the Seireitei.

Therefore, I wanted to ask, how does this Hollow's ability to suddenly appear and vanish differ from the previous one? Also, Captain Shiba disappeared alongside the Hollow. Where are they now? Is Captain Shiba still alive?"

As Toshiro spoke, Kyōraku's expression grew increasingly grim.

"Vice-Captain Hitsugaya, this situation is entirely different from the previous incident. You see, the last time a Hollow appeared in the Seireitei, it used its abilities to disguise itself as a Shinigami it had devoured, infiltrating the Seireitei through Rukongai.

But based on your description, this Hollow seems to have mastered a method of directly entering the Seireitei, opening a Garganta within our territory."

Indeed, for Kyōraku, the fact that the Hollow had taken Isshin Shiba with it suggested that it had opened a Garganta to drag him into Hueco Mundo.

However, what Kyōraku didn't mention to Toshiro was that for a Hollow to open a Garganta to the World of the Living or the Soul Society, it required a "spiritual beacon" to lock onto.

Otherwise, a Hollow could easily lose its way within the Garganta, ending up in an unknown location.

This was why Hollows traveling from Hueco Mundo to the World of the Living often appeared near individuals with spiritual pressure.

Those spiritual pressures served as their beacons.

Typically, any Hollow in Hueco Mundo could use a Garganta to reach a location with detectable spiritual pressure.

But the Seireitei, as the headquarters of the Soul Society's Shinigami, had naturally taken precautions against such intrusions.

All the buildings within the Seireitei were constructed using Sekkiseki, a special stone that could decompose spiritual pressure. To damage these structures, one would require the strength of a seated officer or above.

Moreover, surrounding the Seireitei was a massive wall, imbued with a powerful defensive barrier—the Shakonmaku.

The Shakonmaku's purpose was to contain the spiritual pressure of the Seireitei's Shinigami, preventing it from leaking out.

This not only protected the residents of Rukongai surrounding the Seireitei but also effectively concealed the Seireitei's presence from the three worlds.

Hollows in Hueco Mundo couldn't detect the spiritual pressure within the Seireitei and couldn't open a Garganta to invade.

Even the ancient Hollow King, a millennium ago, had first appeared in Rukongai, attacking the Seireitei from there.

But now, a Hollow that wasn't even a Vasto Lorde had opened a Garganta within the Seireitei. Kyōraku didn't believe for a moment that it could have done so without assistance from someone within.

"Sigh…"

Kyōraku let out a weary sigh. He had a feeling that the Seireitei's peaceful days were numbered.

…

"This is… the World of the Living?"

While charging into the Garganta after the Hollow had been risky, Isshin Shiba had been confident in his ability to return to the Soul Society from Hueco Mundo.

He would simply kill the Hollow, find the stationed Expeditionary Force, and use their Senkaimon to return to the Seireitei. But to his surprise, he hadn't emerged in Hueco Mundo. He was in the World of the Living!

"Roar!"

The Hollow, White, let out a deafening roar and charged towards him.

Clang! Clang!

White's movements were swift, his attacks relentless, pushing Isshin onto the defensive.

"Is this thing really a Hollow?"

The more he fought White, the more astonished Isshin became. Its fighting style was identical to a Shinigami's.

If not for its Hollow shell, its bull horns, and its bone mask with its red and black stripes, Isshin would have sworn it was a Shinigami!

And he wouldn't have been wrong.

While White was a Hollow, it had been created by Ailin using the Hōgyoku's power, its soul was a fusion of Shinigami reiatsu.

After Ailin had entrusted it to Sōsuke Aizen, Aizen had fed it even more Shinigami souls.

It could be said that, besides its Hollow essence, everything about White was derived from Shinigami. Even its combat instincts were primarily Shinigami-based.

Clang!

Having realized he was outmatched in his base form, Isshin deflected one of White's attacks, using the momentum to leap backward. Then, he called upon his Zanpakutō.

"Burn—Engetsu!"

"Roar!"

Flames erupted from his blade, engulfing it in a fiery inferno. Upon releasing his Zanpakutō, Isshin's spiritual pressure increased fivefold. Wielding his blazing sword, he charged towards White.

"Getsuga—"

Shhh!

Just as he was about to unleash his Getsuga Tenshō, Isshin was struck from behind. Blood splattered from his back.

"Damn it! Who's attacking me?!"

He plummeted from the sky, but before he could turn to see who had ambushed him, White renewed his assault.

Below them, a girl with medium-length hair, wearing a school uniform, was rushing towards the battle.

Seeing Isshin about to be struck by White's Cero, she raised her hand. A bow, formed from spiritual energy, materialized in her grasp.

Boom!

Her arrow intercepted White's Cero and detonated mid-flight.

"Roar!"

Spotting the girl, White abandoned Isshin and charged towards her.

…

The next day, while Toshiro Hitsugaya was working on paperwork in the Tenth Division captain's office, he received a summons to attend a captains' meeting at the First Division barracks. When he arrived, he saw Ailin standing outside.

"Teacher," he greeted respectfully.

"Hahaha, Toshiro, long time no see. You've grown taller." Ailin ruffled Toshiro's hair.

Toshiro, usually annoyed by comments about his age, didn't mind when it came from Ailin and Haruko Kuchiki. After all, while he had refused to be adopted by them, they treated him like their own child.

"Come home for dinner sometime."

"If you don't, Haruko might storm the Tenth Division and accuse Captain Shiba of abusing you."

"No, Captain Shiba is good to me," Toshiro replied, thinking back on his time with Isshin. While Isshin could be impulsive, his rapid promotion to vice-captain was due to his captain's favor. He simply wished Isshin was a bit more reliable.

"Let's go, we'll see what Head-Captain Yamamoto has to say today," Ailin said, leading Toshiro towards the captains' meeting chamber.

In fact, even before Yamamoto had spoken, Ailin already knew what the meeting was about.

After all, he had witnessed Isshin Shiba's battle with White.

While he hadn't followed them to the World of the Living, he knew that Isshin wouldn't be returning to the Seireitei for at least eighteen years.

As expected, once the captains had assembled, Mayuri Kurotsuchi dropped a bombshell.

"What? Captain Shiba of the Tenth Division is dead?"

Toshiro was stunned. He stepped forward, approaching Kurotsuchi.

"That's impossible! Captain Shiba was fine yesterday. He went to chase after a Hollow. How could he be dead?"

"Hmph, Vice-Captain Hitsugaya, are you questioning my expertise?" Kurotsuchi snorted coldly.

When it came to scientific research, he believed that only Kisuke Urahara could rival him. As for the others, they didn't even understand the basics of science. What right did they have to question him?

Not even "that individual's" disciple could escape his disdain.

However, to make his statement more convincing, Kurotsuchi presented his evidence.