"From the start, I couldn't sense its Reiatsu."
Aizen crouched beside the monster's corpse, his expression grave.
"Judging by the characteristics of the outer Hierro, it should belong to a Hollow, yet analyzing it at the soul level, it belongs to a normal Soul Reaper's soul."
"Furthermore, the soul was modified, giving it extremely strong concealment abilities."
"The source of this ability is likely a Zanpakutō."
Aizen did not question Naraku Sora further. Everyone had their own secrets, and he was no exception.
Even if they were friends who talked about everything back in the Academy, the relationship between them had changed after joining the Squads.
The past was the past, and people had to live in the present.
Aizen could not let Naraku Sora participate in his plans; otherwise, the final result would likely be them turning against each other.
To the side, Naraku Sora looked realized: "Stuffing a Soul Reaper's soul into a Hollow's body, letting the two powers fuse, and then creating such a monster."
Aizen looked at him with some surprise. "Although a bit far-fetched, it can be understood that way."
"An artificial monster."
Naraku Sora's expression immediately became serious, and he simultaneously understood why he had smelled the monster's scent.
Because, in a sense, he and this thing were of the same kind.
They both possessed the power of a Hollow, and they both had bright futures.
Immediately afterward, under Aizen's puzzled gaze, a certain someone looked at him with a face full of seriousness:
"Sōsuke, then you should be able to find the mastermind behind this, right?"
As he spoke, seeming afraid that Aizen would not agree, Naraku Sora hurriedly added another sentence.
"This is a good brother's only request in this life, please, you must agree."
Aizen: "..."
He didn't know what kind of fit this guy was throwing again.
But he had heard similar dialogue countless times back in the Academy.
Bringing food, skipping class, after-school tutoring, sparring with each other, and so on.
Whenever a request was involved, this guy would attach the "only request in this life" prefix.
Although Naraku Sora was troublesome, strangely enough, Aizen did not find it repulsive.
Because he could truly feel that pure friendship, unadulterated by a single shred of self-interest.
Perhaps this was the purity of their student days.
Countless images flashed through Aizen's mind. After a moment of contemplation, he nodded.
"I'll try."
Naraku Sora grinned. "As expected of the close friend I acknowledge. Next time, I'll bring you the special tofu dish from the Central Great Underground Prison cafeteria."
Aizen continued to examine the deformed monster whose skull cap had been lifted open.
It possessed features of both a Hollow and a Soul Reaper, yet belonged to neither. From a purely technical perspective, this could only be considered a failed product.
But its existence gave Aizen a certain degree of inspiration.
Although the current him had not yet grown to his true upper limit, he could already see that future.
If he wanted to change this rotting world, breaking the limits of a Soul Reaper was something that had to be done.
Perhaps this data could be useful.
Aizen calmly dismantled the monster's corpse, allowing fresh blood to stain his hands and slippery viscera to flow past his fingertips.
He attempted to find clues within.
Any technological modification would leave traces; even the most brilliant scientist was no exception.
Before long, he made a discovery.
"There is a Reiatsu on the heart that definitely does not belong to this individual. Unless something unexpected happened, it should be related to the mastermind."
As he spoke, Aizen dipped his finger in a bit of blood and began to draw symbols on the ground.
"Heart of the south, eye of the north."
"Finger of the west, foot of the east."
"Arrive with the wind and depart with the rain! Bakudō #58, Kakushitsuijaku!"
The moment his voice fell, countless strands of spirit particles burst forth from the symbols on the ground. Expanding outward at a speed difficult for the naked eye to catch, they flew toward the end of his line of sight.
Aizen stood up and looked in the direction where the spirit particle threads disappeared.
"Let's go. Following the guidance of Kakushitsuijaku, we should easily be able to find the mastermind responsible for all this."
...
...
As an important component of Soul Society, Rukongai contained souls from all over the world and even different eras.
Including but not limited to local residents.
Its population was so large it was impossible to count. If one were to search one by one, it would be no different than looking for a needle in a haystack, enough to make any Soul Reaper responsible for the investigation despair.
Especially for a combatant like Naraku Sora, who was not good at strategy, there was no place to start.
Fortunately, his good brother was there.
The two followed the guidance of Kakushitsuijaku all the way, eventually arriving at District 12 of West Rukongai, Izuhara.
Finally, Naraku Sora stood on a bustling street, gazing into the distance where the spirit particle threads vanished.
There stood an exquisite building that stood out like a crane among chickens compared to the other houses. Lanterns emitting pink light swayed in the wind, and the ambiguous sounds of crowing continued uninterrupted.
It was a high-class pleasure district that Naraku Sora had never visited since coming to this world.
Decadent sounds drifted constantly from within the gallery. One could vaguely see beautiful women wearing loose kimonos snuggling up to the people beside them, laughing and playing.
Seeing this situation, Naraku Sora rubbed his hands together, eager to give it a try.
Aizen fell silent again.
Even if you beat him to death, he never would have imagined that the mastermind who developed that kind of monster would be hiding in a place like this.
He lifted his foot to leave, but was grabbed by a certain someone with quick reactions, who spoke with earnest gravity:
"Good brother, running away from battle isn't your style."
"You don't want to see the mastermind remain at large, do you?"
"I'll keep watch for you outside." Aizen attempted a final struggle.
Naraku Sora rejected it directly: "No way. What if there's a tough guy inside I can't handle? If we're together, we can look out for each other."
While speaking, he was already dragging the good-natured Aizen toward the utterly depraved high-class establishment—
Paradise House.
Silhouettes moved inside the gallery; everyone was busy with their own affairs, and no one noticed the two Soul Reapers who had snuck in.
Naraku Sora knew the ropes well, acting like an experienced hand. He waved his hand and summoned two beautiful geishas.
"Open a quieter room; it's my brother's first time here."
A look of understanding immediately appeared on the geishas' faces, and they walked ahead to lead the way for the two.
Aizen wanted to speak but stopped. The words at his lips could only turn into a helpless sigh.
If news of today's events got out, he would have to consider crafting a new persona.
Since things had come to this, they might as well get the job done.
Crossing through several corridors, the geishas led the two to an extremely secluded private room.
As soon as they entered the room, Naraku Sora stretched out his dishonest hands and directly delivered a hand chop to each of them.
Having done this, he looked at Aizen and spoke with a face full of righteousness:
"Let's go, time for business."
For some reason, seeing this scene, Aizen breathed a sigh of relief. He directly activated Bakudō #58, Kakushitsuijaku again. The spirit particle threads penetrated the wall, heading straight west.
The two concealed their Reiatsu and walked in the indicated direction.
They continued until they arrived in front of a Kidō barrier emitting a faint glow.