Hueco Mundo. Las Noches. Underground Laboratory.
Above ground, the clash between titan-class beings had left ripples in the air—but none of that seemed to touch this place. Here, Szayelaporro Granz, the leading scientific mind among the Menos, was immersed in his latest research.
Across the room, seated elegantly at a crimson mahogany desk, was a man dressed in Shinigami robes, reviewing a research report with a composed expression.
"Aizen-sama."
Higashi Shuuichi pushed open the laboratory door, walked directly over to the desk, and bowed with practiced formality.
"Have you reached the level where you can face Baraggan head-on?"
Aizen didn't lift his eyes. His voice was calm, casual.
"No, Aizen-sama. You know my capabilities. To defeat Baraggan, I'd need either an anti-Baraggan Bankai crafted specifically for him… or to overwhelm him with pure reiatsu. As I am now, neither option is within reach. That scene earlier was nothing but theatrics. If I don't act like that, he's going to try something every time I visit Hueco Mundo—and frankly, I'd rather not deal with that."
Shuuichi answered truthfully.
There was no point hiding anything from Aizen. He was completely bound to this side—concealment only made things worse. The only reason he dared to feint a Bankai just now was because he'd sensed Starrk nearby. He knew Aizen would never allow him to release his Bankai so openly in Las Noches.
Especially now.
The Gotei 13 had begun striking Hueco Mundo with renewed force following the Noble Hunt Incident, and there was no telling which reconnaissance squad might be lurking nearby—perhaps even someone who recognized his spiritual pressure.
Only after hearing this did Aizen finally glance up from his report and shift the subject.
"Tell me what you learned during the Noble Hunt."
As expected.
Aizen couldn't care less about Baraggan's antics. In his eyes, Baraggan was no different from a Lieutenant-level annoyance. If Shuuichi were to be killed by such a relic, then he never deserved to be a pawn on Aizen's chessboard to begin with.
Shuuichi straightened up.
"The Gotei 13 is still incredibly powerful. Even without the Captain-Commander taking the field, just six captains were enough to repel both Baraggan and Starrk."
He paused.
"Also, based on what I observed, Kyōraku Shunsui of the 8th Division and Shihōin Yoruichi of the 2nd Division didn't fight at full strength. The others—Muguruma Kensei, Kenpachi Kuruyashiki, Hirako Shinji, and Kamikawa Rennosuke—they, too, were holding back."
Shuuichi's observations came from what his spirit puppets had recorded on the field. As for knowing the true upper limits of those Captains? That'd be too suspicious for someone in his position.
"Starrk reported the same," Aizen replied, setting the research paper down. "Especially regarding Yoruichi. He's convinced she didn't even reveal her trump card."
Shuuichi's peripheral vision flicked to the report Aizen placed down. As expected, it was a document penned by Szayelaporro—an analysis of souls.
So Szayelaporro was already neck-deep in spiritual research.
Which meant… Ilforte Granz, Szayelaporro's "elder brother," would soon be born.
And it also meant Aizen's interest in souls with Shinigami potential—especially those from Rukongai—was escalating. Previously, his experiments were confined to reishi manipulation on a surface level. Now… it was about soul structure.
"Do you need my assistance probing them?"
Shuuichi asked, knowing full well Aizen never made idle conversation—not with him, at least. Every word was measured.
Every silence, calculated.
"Probing, yes," Aizen nodded. "But not Yoruichi."
"Then who?" Shuuichi asked—though the answer had already begun forming in his mind.
It couldn't be Muguruma, the Gotei's go-to power scale. And Hirako Shinji was Aizen's old Captain—his capabilities already well known.
The rest were loud, active fighters—easy to read, easy to measure.
Only three remained:
The seemingly indolent Kyōraku Shunsui of the 8th Division.
The quietly enigmatic Unohana Retsu of the 4th.
And the fragile, constantly ill Ukitake Jūshirō of the 13th.
Unohana was a dead end. Shuuichi had spent seventy years under her. She never revealed anything.
Ukitake? Practically invisible, his spiritual pressure too faint to track.
Which left just one.
"Kyōraku Shunsui."
Aizen spoke the name as if it were an afterthought.
Since the beginning, the only Shinigami Aizen ever considered a true threat was Yamamoto Genryūsai. But even he now realized—overthrowing Soul Society required knowing the limits of all its captains, not just one.
That was the next step.
A few years ago, Aizen had come across an experiment log—one someone had tried to destroy. In it, he'd found hints regarding Hollowfication of Shinigami.
Since then, he'd redirected his focus. And Shuuichi, being an exceptionally convenient tool, would now be tasked with some heavier lifting.
"I understand, Aizen-sama. I'll complete the assignment as swiftly as possible."
He offered no protest.
Shuuichi had long since accepted the unspoken truth of working under Aizen: never refuse. No matter how ludicrous the command, Aizen didn't want analysis. He wanted obedience.
Shuuichi prided himself on being a model employee.
And honestly, this was a lot more appealing than being told to "go test Baraggan again."
For a moment, he felt the slightest flicker of smug relief.
Which lasted all of one second—before Aizen's next line made him freeze in place.
"I recall you said you took seven days of leave?"
"Yes, Aizen-sama. Is there something you need?"
"The Gotei sent one captain and a vanguard unit into Hueco Mundo."
"…Yes?"
"They're not going back."