If the acquisition of the Mangekyo Sharingan was somewhat expected, then the appearance of White Zetsu was an unexpected surprise for Aizen.
He stood in the center of the laboratory, his gaze exceptionally focused beneath his thick glasses as he looked at the slowly developing body in the cultivation tank.
"Truly an astonishing creation."
Yakushi Kabuto stood beside him, looking at the lines of data on the computer screen, and couldn't help but murmur:
"Not only does it possess excellent Chakra compatibility, but it also has a carrying capacity that surpasses ordinary Jonin. If it were made into a weapon, it would probably be equivalent to the legendary Chakra superconductor, wouldn't it?"
"Moreover, it's a... life form?"
At this point, even Yakushi Kabuto himself didn't know how to describe it.
Although it appeared to be a life form on the surface, the data indicated it was closer to some kind of inorganic matter.
He murmured softly, turning to look at Aizen Sōsuke in front of him.
With this Lord's talent, what exactly did he plan to create with such a thing?
"Not a life form."
Just as he was thinking, he heard Aizen Sōsuke suddenly speak, his eyes also showing a hint of amazement:
"This is an unimaginably complete Yang Release creation, Kabuto-kun."
Even in his previous life, even by utilizing the spirit particles that form the basis of human souls, it would be difficult to coalesce such a complete individual consciousness.
The standard product of chaotic spirit particles should be monsters like Hollows.
It must be said.
This world, in some aspects, indeed has its merits.
The only thing he couldn't believe was, was this truly a product that ordinary humans could create?
Creating life out of nothing, coalescing will out of nothing—this was not a simple transfer and induction like cloning or transplantation.
Instead, it was a... creation.
From an academic perspective, the mere work they were currently observing was enough to open up a new field of research.
So, how exactly was it created?
Aizen grew increasingly curious.
Just as he was thinking.
"Beep, beep."
A faint alert sound came from the machine.
Aizen promptly gave a command: "Inject Gene No. 1, begin human gene fusion."
"Yes."
Soon, Yakushi Kabuto swiftly operated the machine.
As the genes were injected through the Chakra pathway, the White Zetsu construct in the cultivation tank began to undergo a violent boiling reaction.
Under the immense Yang Release Chakra, which represented the essence of life, countless distorted physiological structures regenerated and shed from its body surface.
If he were just an ordinary human, the experiment would have already ended at this stage.
However, the tenacious vitality possessed by White Zetsu itself was far beyond what ordinary people could compare to.
The data on the experimental platform was also constantly updating.
This experimental process continued under their operation.
It lasted for more than ten days... "Lord Aizen."
"Gene No. 197 is entering a stable state."
Yakushi Kabuto reminded him with a steady voice.
For a Ninja, long periods of high-intensity repetitive labor were not difficult.
Aizen looked at the body in the cultivation tank, his expression growing more satisfied.
At this moment, what appeared before them was a tall, robust male body with pale skin, deep silver hair, and a short horn above his brow.
"Gene No. 197 belongs to the Hyuga Main Family remnants collected earlier."
"Indeed."
"Still inseparable from them, huh."
Aizen thought, his gaze slightly lost in thought.
This was a world where bloodlines reigned supreme.
Ninja, as primitive people who could naturally use energy weapons, had all their secrets hidden deep within their genes.
From a biological perspective, they must all possess a common ancestor that can be traced back.
Among them, the Hyuga Clan's identity was the most special.
Even more special than the Senju and Uchiha.
Because they inherited the most prominent feature of this ancestor.
The Byakugan.
With Hyuga Hizashi as a subordinate, many ancient secrets were no secret to Aizen.
Whether it was the truth of Goddess Ōtsutsuki, the true identities of the Senju and Uchiha, or the essence of the Hyuga Clan.
The Hyuga Clan were the 'branch family' of the Ōtsutsuki Clan, who resided on the moon, left behind in the Ninja World.
Aizen Sōsuke had already learned this from Hyuga Hizashi.
As the head of the Hyuga Clan's branch family, and also the younger brother of the current clan head, Hyuga Hiashi, the secrets he knew were far more numerous than ordinary people could imagine.
After all, his rebellion against the Main Family didn't begin only after his son was born.
He even knew that the Hyuga Clan, to this day, maintained some level of connection with the Ōtsutsuki Clan residing on the moon.
He just didn't know the specific method of contact.
"Goddess Ōtsutsuki, Six Paths Sage, Ōtsutsuki Clan, Hyuga..."
"And, the god tree factor."
After connecting the various clues, the true history of this world gradually formed in Aizen Sōsuke's mind.
After all, the entire Ninja World's history was only a short thousand years.
Compared to the cycles and evolutionary changes over millions of years he had seen in the Great Spirit Library in his previous life, the Ninja World's civilization could only be considered a newborn cub.
There were no complex problems.
However, the more reality he understood, the deeper Aizen Sōsuke's apprehension grew.
Because this world was too vast, and this star-filled sky was too expansive.
If it truly was as he thought, that there existed a stellar race in this star-filled sky that constantly monitored this Ninja World, a race where a single Ōtsutsuki Clan member could change the entire civilization's level through some means...
Then, the waters here were simply too deep.
His vision had never been confined to this narrow world.
The only thing worth celebrating was that he had, from the very beginning, come into contact with the most fundamental power of this world.
Chakra.
Aizen Sōsuke thought this, slowly raising his head to look at the body in the cultivation tank before him, and extended his hand towards it.
Then, a soft 'hum' sound was heard from within the cultivation tank.
The Chakra guiding solution filling the cultivation tank continuously receded.
The body standing in the center of the cultivation tank gradually raised its eyelids, meeting the gaze of the figure before it.
Its eyes were empty and lifeless.
"Lord Aizen?"
Yakushi Kabuto looked at him, puzzled.
The next moment.
The body, completely devoid of consciousness, suddenly made the same movement as Aizen, raising its hand and pressing it against the glass surface of the cultivation tank.
Yakushi Kabuto's expression immediately froze.
"Crack, crack, crack..."
Under the pressure of his palm, large, dense, spiderweb-like cracks suddenly appeared on the tempered glass surface, pushing forward little by little under Yakushi Kabuto's disbelieving gaze.
Until finally, it let out a crisp 'bang' sound.
With mere pushing force, it completely shattered the glass before it.
"This..."
Yakushi Kabuto stared at this scene in astonishment.
The silver-haired figure stepped down, its eyes still closed, its bare feet treading among the glass shards, yet without a single scratch.
Finally, it stopped in front of Aizen.
"Not bad."
Watching this scene, Aizen nodded slightly.
If it were purely based on physical ability, many Taijutsu-type Jonin probably couldn't even compare to him.
"Lord Aizen, what exactly is this?"
Yakushi Kabuto said, his steps unconsciously moving closer to him.
"Shadow Possession Jutsu."
"This is a new technique I've developed."
"The Yang Release consciousness that originally existed in this body has been completely stripped away."
"No need to worry."
Aizen's voice seemed to be always so calm.
This technique largely borrowed from the structural elements of the Shadow Clone Jutsu.
If Shadow Clone Jutsu involved transmitting a portion of consciousness through Chakra into a physical clone to convey information and experience, then his developed 'Shadow Possession' involved injecting this consciousness into an empty shell for long-term control and maintenance.
However, for ordinary people, the spiritual consumption would probably be too heavy, making it impractical for widespread use.
Aizen looked at the quietly standing body before him, suddenly revealing a playful smile:
"Kabuto-kun."
"Yes, I'm here."
Yakushi Kabuto immediately stepped out from behind him.
"You say, if this body appeared in the Hyuga Compound..."
"What reaction would Clan Head Hiashi have?"
Yakushi Kabuto was momentarily stunned by his sudden, tangential question, a look of bewilderment on his face:
"Huh?"