Experiments on Ghosts

Naturally, ordinary ropes could not restrain a demon with such superhuman physical abilities.

Therefore, Sarutobi Hiruzen used special Konoha chains to pierce through its shoulder blades, and he also applied numerous sealing techniques within its body.

Throughout the journey, Sarutobi Hiruzen did not remain idle; instead, he conducted in-depth experiments and observations on the creature known as a demon.

"After a human transforms into a demon..."

"Almost all the cellular structures of the body undergo a complete mutation..."

"They transform into components similar to blood cells."

"Possessing nearly infinite regenerative capabilities..."

"Much like cancer cells..."

Sarutobi Hiruzen's gaze was profound, as if he could see through the body of the Four-Armed Demon before him to the structures within.

"Thus, its form is no longer limited to a human shape; instead, like a tumor, its cells can grow wantonly into any organ..."

"Of course, for the Four-Armed Demon before me, this is impossible."

"Because the concentration of the primordial blood within its body—that is, the blood of Kibutsuji Muzan—is too low."

"Reaching this current level is about its limit."

"Unless Kibutsuji Muzan is willing to give the Four-Armed Demon more of his primordial blood."

"The higher the concentration of that primordial blood within a demon's body, the deeper the degree of cellular mutation."

"And the stronger its vitality becomes."

"Kibutsuji Muzan can even autonomously create brains, internal organs, and other such structures."

Although demons are far inferior to ninjas in terms of combat power, they possess a vitality and a variability in life form that ninjas can never hope to reach.

"It is quite laughable, really; the things Orochimaru has pursued his entire life, this demon has already achieved with ease."

Sarutobi Hiruzen found it somewhat miraculous; this was the wonder of a multiverse.

Things that are incredibly difficult in one world are as easy as reaching into one's pocket in another.

"However, setting aside the fatal weakness of sunlight, demons are not truly immortal."

"At the very least, judging by the vitality within this Four-Armed Demon, it would also fall into a state of decay after a few hundred years."

At this moment, Sarutobi Hiruzen's hands radiated the green light of medical ninjutsu's Yang Release as he probed the demon's internal life force.

"Even Kibutsuji Muzan must have a concept of lifespan; perhaps ten thousand years? Or a hundred thousand?"

"Piu."

Suddenly, a sound like a balloon being popped rang out, causing Sarutobi Hiruzen to shift his gaze from the Four-Armed Demon to another wooden table.

Placed upon it was the robust corpse of a human male; of course, just a second ago, he had still been alive.

But in this second, his heart had burst as if a balloon had been pricked.

"A failure, then."

In these chaotic times, there was no shortage of experimental subjects; one could say it was a paradise for human experimentation.

Sarutobi Hiruzen had selected several enthusiastic soldiers who had drawn their blades on him, placed them on the experimental tables, and injected them with demon blood.

Although it was a failure, there was not the slightest hint of frustration or surprise on Sarutobi Hiruzen's face.

"As expected, the level of this Four-Armed Demon is still too low."

"It was never granted the ability by Kibutsuji Muzan to infect humans and turn them into demons."

"I suppose that while Kibutsuji Muzan is scum, he is not a fool..."

"He understands the principle of not draining the pond to catch the fish; if every demon had the ability to infect others, and the number of infected demons grew too large and ate all the humans..."

"Then wouldn't Kibutsuji Muzan himself starve to death?"

Sarutobi Hiruzen confirmed a hypothesis in his mind.

Unless permitted by Kibutsuji Muzan, an infected demon has no way to infect others.

"In other words..."

Sarutobi Hiruzen had glimpsed the truth behind the creature known as a 'demon'.

"Demons are not actually a biological species like vampires."

"Or rather, demons do not have the concept of a biological species."

"Even Kibutsuji Muzan and the other demons do not share a parent-offspring relationship."

"In essence, there is only one collective of demons in the world, and that is Kibutsuji Muzan."

"All other demons are merely products of the primordial blood he shares from his own body."

"That is why Kibutsuji Muzan's control over his subordinate demons can reach such an extreme degree."

"Manipulating thoughts, restricting the ability to infect, and setting genetic limitations."

Thinking of this, Sarutobi Hiruzen felt an even greater aversion to becoming a demon.

"No matter how powerful one was as a human."

"Once you become a demon, you are destined to be enslaved, or even parasitized, by Kibutsuji Muzan."

"Not only your life and death, but even your very thoughts will no longer be your own."

However, such a situation was not without its exceptions in the world of Demon Slayer.

A sharp glint flickered in the eyes of Sarutobi Hiruzen.

"Unless."

Suddenly, a clear, slightly youthful female voice drifted from outside the tent.

"Lord Sarutobi..."

"The sky has grown dark..."

"We have prepared food for you."

Sarutobi Hiruzen remembered; this girl was the daughter of the caravan leader.

"Just leave it at the entrance."

Sarutobi Hiruzen replied casually.

"We have also prepared hot water for you..."

"I wonder if it would be convenient for you to let me come in and serve you?"

Hezi's voice sounded again, this time carrying a hint of hazy ambiguity and seduction.

"Then come in."

A steady voice replied, agreeing to Hezi's request this time.

By the time Hezi and the servants behind her entered with the water and food, the interior of Sarutobi Hiruzen's tent was already completely empty.

There was no trace of the Four-Armed Demon or the test subjects from just a moment ago.

"My lord."

Hezi bowed slowly, her loose kimono vaguely outlining her alluring curves.

Sarutobi Hiruzen's expression remained unchanged as he spread his arms, signaling for Hezi to help him undress and bathe.

The reason he agreed to let Hezi in was that ever since he entered the world of Demon Slayer, he had been on the road for days and hadn't had a proper wash.

His modern soul found that somewhat difficult to accept.

Seeing Sarutobi Hiruzen being served with such familiarity, Hezi's eyes sparkled, and she became even more convinced that this Lord Sarutobi was of extraordinary status.

In truth, Sarutobi Hiruzen was indeed of extraordinary status; in the world of Hokage, whether as the head of the Sarutobi Clan or as the leader of Konoha, he had lived a life of privilege, served by others.

After bathing, Sarutobi Hiruzen began to eat.

Although he carried enough Military Ration Pills, who would eat that stuff if they could have a proper meal?

Even though the food placed before Sarutobi Hiruzen was not lavish, one could not demand much in this small country.

After all, even the emperor of this little nation was just gnawing on salted fish every day.

Meanwhile, Hezi stood behind Sarutobi Hiruzen, massaging him with just the right amount of pressure.

"Lord Sarutobi..."

"Are you a samurai of the Sanada Clan?"

Hezi was still too young, and unable to suppress her curiosity, she couldn't help but ask directly.

Sarutobi Hiruzen found this somewhat amusing upon hearing it.

He had only kept the surname Sarutobi, yet it had caused these people to let their imaginations run wild.

But there was no helping it; in this era, the reputation of the Sanada surname was something even a daimyo could not rival.

Sarutobi Sasuke was the number one warrior under the Sanada Clan, and in official history, he was a ninja of the Koga Clan.

In fact, when that author AB created the world of Hokage, he was influenced by that very figure when he designed the character of Sarutobi Hiruzen.

So, in a way, Sarutobi Hiruzen really did have some connection to the Sanada.

Please follow this story, or the book will die! I beg you.