(T/N: Chapter 5 out of 6!!)
That day, Nanatsuki once again examined Saitō Rei's spiritual body.
Her condition was stable, which gave him peace of mind. All that remained was to cultivate Batsu'unsai's Reishi Shell, then he could transplant the Spiritual Pressure Core, and her injuries would be healed.
However, Katori Batsu'unsai was far stronger than Saitō, and her Reishi Shell would require more time to cultivate.
Now that he had a viable solution, Nanatsuki wanted to restore Batsu'unsai as close to her full strength as possible.
"Miss Rei, the Saitō clan has a long history. Surely your family owns some texts describing the ancient era? I'm very interested in that sort of thing—would it be possible for me to read them?"
Not long ago, he'd spent time browsing the libraries of the Shiba and Shihōin families, reading many historical records.
Through that, he learned of some secrets from the ancient past.
To maintain the world's balance, the Soul King had set up three ritual arrays—one in Soul Society, one in Hueco Mundo, and one in the World of the Living.
These three arrays were in fact also connected to three seals within Hell.
But even after poring through the Shiba and Shihōin records, Nanatsuki hadn't found any details about the seals within Hell.
He remembered that Saitō Furaofushi had mentioned that aside from her grandmother, the Saitō family once had an ancestor whose Zanpakutō ability was related to Hell.
Thus, their archive supposedly contained some records about it.
Nanatsuki was hoping to find something noteworthy there.
"We actually do have books on that subject. Are you really into this kind of thing?" Saitō Rei readily agreed to bring him to the archive. "If you want to see them, of course you can. I'll take you there."
A short while later, Saitō Rei led Nanatsuki into the family archive.
The Saitō family had a substantial collection. Rei began introducing the types of books:
"These shelves hold notes on Kidō training."
"Those over there are split into sections on swordsmanship, Zanpakutō, Hakuda, and Shunpo—everything except Kaido, basically."
"If you're interested, feel free to browse."
That was the advantage of a long-standing family: the training notes passed down by their ancestors made it much easier to nurture descendants capable of reaching seated officer level and beyond.
Nanatsuki was especially curious about the Zanpakutō development logs and stopped to browse.
He discovered that the Saitō ancestors had recorded the progress of their Zanpakutō's evolution and abilities, all for future generations to reference.
"As expected of an old family. If any descendants awakened similar abilities, these would serve as a solid guide to accelerate their Zanpakutō development."
"We don't have that many members, so similar abilities are rare. The notes on swordsmanship, Hakuda, Shunpo, and Kidō are usually more important," Rei said with a smile. "But mine is a pretty common wind-type Zanpakutō, so I found some references."
"Wind-types are common, but highly versatile. That's a solid ability to have," Nanatsuki commented casually.
He flipped through the swordsmanship section for a bit but quickly lost interest. The Saitō sword style was fairly average, and the insights too basic for him.
The Kidō notes, however, caught his attention.
There were even records of custom Kidō spells—developed independently by Saitō ancestors.
Of course, just because something was custom-made didn't mean it was stronger than officially recognized spells; most of them had value only in niche situations.
"The books on the ancient era are on the innermost shelf. That area doesn't get many readers. I'll let you browse while I fetch some tea and snacks."
"Thanks!"
"No need to thank me. You saved my life, Nanatsuki-kun. This is the least I can do..."
Rei pointed him to the right shelf and left the room.
Nanatsuki didn't immediately head for the ancient texts. Instead, he kept flipping through the Kidō notes.
"A Kidō that converts Reishi into ice... That might come in handy... Summer's almost here, after all. I could make chilled drinks."
"A spell that draws humans closer... Its structure resembles the spell used to repel them..."
"A light-producing Kidō that lets non-spiritually aware humans see spirits... That's actually kind of interesting."
"A Kidō that summons Hell Butterflies from Hell?"
Nanatsuki's interest spiked.
Hell Butterflies guided souls between the World of the Living and Soul Society.
They also served as a messaging system. While the Denreishinki was the standard tool, the Gotei 13 also used Hell Butterflies to relay messages.
As far as Nanatsuki knew, Hell Butterflies were originally native to Hell. They were natural denizens of that world.
When the Shinigami discovered their ability to guide spirits and carry messages, they tamed them and began cultivating colonies in Soul Society.
"So the ones summoned by this Kidō... are they the untamed kind?" Nanatsuki kept reading.
"Untamed Hell Butterflies can track down 'sinner' souls—those condemned to Hell—and lead them there."
Tamed butterflies had lost that function.
Nanatsuki rubbed his chin. 'What use could this ability serve?'
'If I ever want to enter Hell, this would save me the trouble of finding the Gate of Hell...'
Finding the Gate was no easy task.
It only opened when a sinner's soul appeared in the World of the Living.
But with this spell, he could summon an untamed butterfly that would lead him directly to the Gate—no need to search blindly.
"Hell Butterflies naturally have interdimensional traversal abilities... What a fascinating species."
Nanatsuki took detailed notes on the spell. It might be useful later.
There were a lot of these "life hack" type custom Kidōs on this shelf. Nanatsuki found them amusing and copied down several.
Some time later, Saitō Rei returned with tea and snacks. She didn't interrupt—just quietly set them down and left.
After finishing the Kidō section, Nanatsuki skimmed through the Hakuda and Shunpo shelves.
But he had already read more complete records at the Shihōin estate, so he quickly lost interest again.
He moved on to the final bookshelf—the one holding records about ancient history, legends, and exploration logs.
This collection wasn't as extensive as what he'd found in the Shiba or Shihōin archives. But the focus was different.
The Shiba and Shihōin mostly recorded information about the Soul King.
The Saitō clan, however, had notes about explorations into Hell.
"So it was a Saitō ancestor who first discovered the Hell Butterfly species..."
"Hell beings aren't immortal... If they die and lack Hell Energy to resurrect, their will fades, and their Reishi becomes part of Hell itself..."
Nanatsuki even found a map of Hell in one of the books.
It had been charted by a Saitō ancestor.
It only covered a small portion of Hell, but that alone was incredibly valuable.
This was the first time Nanatsuki had seen a Hell map in Soul Society.
He immediately pulled out a scroll and copied it.
"This whirlpool... could that be the Eye of Hell that Saitō Seiko discovered?"
The map didn't name the location. It simply marked a whirlpool in a river with a note: A terrifying vortex. Do not approach!
Nanatsuki suspected this was the same Eye of Hell that Seiko had found. Maybe she'd seen this map herself, which led her to locate it.
A moment later, Nanatsuki found a second map.
He'd never been to Hell, so he had no frame of reference for what the places were. But in the lower-left corner, a distinctive Stone Forest was illustrated—pillars of stone stacked together.
Beside it, a note read: A place where Hell Energy gathers!
Nanatsuki thought this might be an extraordinary location and copied it as well.
Both maps were tucked inside the same memoir, authored by a single Saitō ancestor.
The memoir also included commentary on the maps.
As for the whirlpool in the river, the ancestor hadn't explored it further.
He'd thrown a Hell creature into it and watched it vanish. But without Seiko's ability to see through other beings' senses, he didn't dare go in himself. So he ended the expedition there.
"The vortex in that river is almost certainly the Eye of Hell... And we've confirmed that it's one of the three seals."
As for the Stone Forest:
The ancestor had marked it as a place where Hell Energy surged.
Hell creatures gathered there regularly, drawn by the energy.
Many powerful entities resided there. It was a dangerous place.
Unwilling to clash with Hell's elite, the ancestor left without probing deeper.
'I'll have to explore that Stone Forest someday... It might be another seal location.'
The seals in Hell were tied to the Lord of Hell. If Nanatsuki had the power, he wanted to deal with them before the Lord fully revived.
The Lord of Hell was once powerful enough to rival the Soul King. Even now, just a disembodied will drifting through Hell, he remained extremely dangerous.
Nanatsuki was still at captain-level strength, and while the crisis wasn't yet imminent...
He had no intention of charging recklessly into Hell.
First, he needed to consolidate his operations in Soul Society, Hueco Mundo, and the World of the Living—and reach the level of a Transcendent.
"Sosuke, which group are you in?" Shiba Isshin squinted at the posted bracket, trying to find his name.
"Still looking..." Aizen Sōsuke was also studying the list.
The Shin'o Spiritual Arts Academy Live Blade Tournament group brackets had just been released, and the matches were about to begin.
"Found it. I'm in Group Five," Aizen said, skimming the names of his groupmates. No one stood out. "None of you are in the same group as me."
"Nice! I'm in Group Three!" Shiba clenched his fist. "Just like savoring good food—save the best for last. We'll see each other in the quarterfinals!"
He felt relieved. At least he wouldn't run into Komamura Sajin or Aizen right away.
Though he was confident he could beat them, he knew both were formidable, and a misstep could end in an upset.
He had been practicing a new trump card. It was risky—definitely not something to waste in the early rounds.
He wanted to win this tournament and graduate in his first year!
The others were also checking their groups.
"I'm in Group One," said Komamura.
"Oh no, I'm in Group One too!" Yadōmaru Lisa groaned, clutching her head.
Komamura was already strong, and now that he'd learned Shikai, she didn't stand a chance.
She'd seen his Shikai. Its power was immense.
If Komamura got serious, she might get one-shot.
"I... I'm in Group One too!" Azashiro Sōya stared at the list, stunned.
Doomed.
He'd been placed in the same group as Komamura and Lisa!
Even in practice, he couldn't beat either of them.
Even though he could use his specialty, Kidō, in this tournament, he still doubted his chances.
Komamura's Shikai made him nearly untouchable for Azashiro.
And Lisa? She was ahead of him in everything but Kidō. He didn't even feel confident beating her.
"I'm in Group Six!" Kotetsu Isane said happily, relieved to be separated from the others.
"Group One is a death group! Terrifying!" Shiba laughed. Not his problem, luckily.
"Even if you don't win your group, the top three scorers get to challenge other group winners. Don't stress too much. Just perform normally," Aizen said with a smile.
"Group One really is cursed... I feel bad for you guys."
A voice chimed in nearby.
They turned to see a young man with black hair and sunglasses, buzz-cut hair, and sharply chiseled features.
He had a bit of a roguish air, with a messy mustache to match.
"Meeting me, Iba Tetsuzaemon, is your biggest misfortune!" he grinned.