In truth, the demonstration just now was far from as simple as Satsuki had described.
Hidden within it was one of her still-theoretical secret techniques: the most basic prototype of Infinite Control: Eight Gates Human Puppet.
The muscular breakdown and bleeding that appeared on the test subject earlier were the direct result of Satsuki using her infinite control technique in conjunction with the Byakugan's insight into the chakra network to forcibly open the gates within the subject's body.
At present, while the Eight Gates technique was hailed in the Naruto world as one of the strongest taijutsu styles—discussed alongside Kaguya's Eighty Gods Vacuum Attack in her past life—both were heavily dependent on the user.
Eighty Gods Vacuum Attack need not even be mentioned—without Kaguya's body, an ordinary person couldn't even attempt it.
The Eight Gates, on the other hand, temporarily unlock powerful strength by releasing the body's chakra restraints.
Though it can instantly grant strength dozens of times greater than Kage-level, the power of the Eight Gates ultimately depends on the user's original capacity—it merely multiplies what is already there.
Thus, the power one gains after opening the Eight Gates differs from person to person. Once the final gate, the Gate of Death, is opened, the user dies as their life force is completely burned away.
Might Guy, the man who almost kicked the story to its end, was the greatest representative of the Eight Gates. But beyond him, no one else ever reached the level where a mere mortal body and mortal technique could wound a Six Paths-level opponent.
Truth-Seeking Balls essentially rendered anyone below Six Paths level—lacking Sage Arts or space-time ninjutsu—utterly insignificant.
Over the past few years, Satsuki had researched the human body using various acquired test subjects. She had more or less mapped out the Eight Gates' locations and methods of opening.
But the problem was that even with all gates opened, untrained individuals barely gained any significant strength. Comparing them to a regular Kage would be laughable.
Reaching the level of an elite jonin was rare, and without exception, all test subjects died afterward.
Most couldn't even survive the opening of the fifth gate.
So, in Satsuki's current view, this technique was still far from complete.
Since it didn't meet her expectations, she didn't mention any of it to the system.
The latest batch of test subjects had already been used up. The one earlier was actually the last of them—and despite being of rare quality, he only barely managed to endure until the opening of the sixth gate before death.
But even that subject was too weak, lacking potential. His body didn't even emit the green steam that typically signifies the opening of the Gate of View.
That said, the price difference between ordinary people and ninjas was massive. Depending on their strength in life, a ninja could be worth hundreds or even thousands of times more.
And if word got out that she was using live ninjas as research materials, even in this Warring States era, Satsuki would face considerable trouble.
To minimize risk and for the sake of research, her early test subjects were mostly ordinary people, with a few rogue shinobi or clan defectors.
Of course, occasionally encountering some "delivery men" along the road was a welcome bonus.
Clack, clack...
Mechanical sounds came from the puppet artist inside the room as its gears ground against one another. It approached Satsuki and presented the finished portrait to her.
Satsuki unrolled the scroll and examined it carefully. When she saw the pair of glaring white eyes in the painting, she frowned.
Apparently, these puppets were getting ahead of themselves—but their intelligence hadn't caught up.
"Paint on a silk blindfold over the eyes, then deliver this portrait to the lord of Iga Castle."
After handing the self-portrait to the puppet artist, Satsuki returned to her room.
Early the next morning, Satsuki used her wireless transmission control technique from the top of the castle keep to remotely command a squad of samurai puppets. In full formation, they departed with grandeur, visiting the nearby lord of Iga Castle under the guise of a noble.
During the conversation, Satsuki used the puppet to present her self-portrait as a gift.
As expected, through the puppet's perspective, she caught a brief flash of green light in the other party's eyes.
The plan was progressing smoothly.
After the banquet ended, the lord of Iga Castle, while bidding farewell, subtly expressed to the puppet—controlled by Satsuki—his desire to meet the woman from the portrait five days later.
The puppet responded with a smile that said, "I understand."
Once the mysterious noble who claimed to be of the Ōtsutsuki clan departed, the lord of Iga Castle privately summoned his elite ninja commander, Shirakumaru.
"Shirakumaru, take a look at this painting." The castle lord handed over the scroll.
Kneeling respectfully, Shirakumaru received the painting and examined it for a moment.
"My lord, there is a chakra signature on this painting."
"That is not the point," the castle lord said while fanning himself with his round fan. "I want you to look at the woman in the painting."
"This..." Shirakumaru hesitated, glancing up at his lord before replying, "Though her eyes are hidden behind a blindfold, judging by her posture, bearing, and attire, she appears to be an extraordinarily beautiful woman of noble birth."
"Exactly." The lord of Iga Castle now shed the lecherous demeanor he'd worn before Satsuki's puppet. "I need you to tail her and investigate this clan. Find out their strength, location, main assets, and the scale of their armed forces."
Finally, he tapped the image of the woman in the painting. "And, of course, find out everything about her."
"Understood."
Shirakumaru's figure vanished instantly.
That night...
Satsuki's hidden fortress received a group of unexpected visitors.
"So this is the estate of that so-called Ōtsutsuki noble?"
Leading them was a white-haired ninja wearing a mask and clad in tight black shinobi gear with layered armor and a short blade on his back.
The cold, lethal look in his eyes made it clear he was a true shinobi.
This was the fully armed Shirakumaru.
Four in total, they stood before the looming mountain castle bathed in moonlight.
Gazing up at the majestic structure, Shirakumaru paused. Judging by the size, it was possible the owner was indeed of noble status. But whether they were a great noble was another question entirely.
This place was remote, with no castle town beneath it. In Shirakumaru's experience, the strength behind this estate likely didn't reach the level of a great noble house.
To claim the Ōtsutsuki name without having the matching stature would be considered a major crime among the nobility.
He and his three companions gathered in a circle. One of them, the recon and intelligence specialist, used a summoning beast to get a bird's-eye view of the entire fortress.
In a short time, he produced a full structural map of the castle, marking potential sentry points, and spread it out for the group.
Led by Jonin-ranked Shirakumaru, the others were all Chunins. With their wealth of infiltration experience, the four quickly memorized the layout and moved into action as planned.
It didn't take much effort for them to successfully infiltrate the fortress.
Even after their successful entry, Shirakumaru remained cautious.
As the head of Iga Castle's elite ninja force, his intelligence network was formidable. Yet before this operation, he had no prior information about this so-called Ōtsutsuki clan.
If not for tracking the group that had delivered the portrait, no one would have known that such a grand fortress stood hidden in the deep mountains.
Shirakumaru and his three Chunins were the only members assigned to this mission. For an infiltration and reconnaissance operation, this team was more than adequate.
The four gathered on a tree branch in a secluded corner of the castle grounds. Shirakumaru turned to one of his teammates.
One of the team members, a specialist in tracking jutsu, pressed both hands onto the painting and read the residual chakra signature. Then he performed a secret technique, forming seals quickly and wiping his hands across his eyes.
He scanned the castle once and reported to Shirakumaru, "Captain, I've detected a chakra source matching the painting."
He pointed to the top floor of the castle keep, where a faint light could still be seen.
"The target is likely there."
"Captain, it's too quiet here," said another Chunin, his expression revealing unease. "I have a bad feeling about this mission."
Shirakumaru also sensed something strange in the atmosphere. Though he had seen numerous patrolling samurai guards while infiltrating from outside the fortress, he hadn't detected any signs of shinobi activity.
That was highly unusual.
In the chaos of the current era, everyone knew shinobi were the most efficient 'tools' for defense. The chakra in the portrait indicated that the target was well aware of this truth, and yet, no shinobi presence had been detected so far.
Was it a deliberate misdirection? Or sheer confidence?
Still, as a Jonin, Shirakumaru had confidence in his strength. Even if discovered, he had no fear. He coldly ordered, "Proceed with the plan. Begin the operation."
After dispersing, Shirakumaru made his way straight toward the target. His mission was to locate the woman and capture her alive. Naturally, the keep was the most likely place.
As Shirakumaru cautiously crept along the outer corridor of the keep, a cold female voice rang out from within.
"Fifteen minutes later than I expected. I thought your lord wouldn't bother sending anyone."
As the voice faded, the doors to the keep opened before the stunned Shirakumaru, revealing the woman from the portrait. At first sight, he understood why his usually cautious lord had taken such a bold interest in an unknown noble.
The woman's unparalleled beauty and stunning, graceful figure, paired with a lavish black robe, unmistakably signaled her noble status.
No man could resist such a vision.
Even someone as iron-willed as Shirakumaru couldn't help feeling a flicker of emotion, enough to overlook the cold, detached look in her eyes.
Standing before him, naturally, was Satsuki, who had been waiting like a hunter by the tree.
She glanced coldly at the dazed ninja, then tapped the armrest beside her with a single finger.
Her face was fully visible, and Shirakumaru immediately saw her unusual white eyes.
"Those eyes...?"
Shock flickered across Shirakumaru's face—and then he found his body walking forward uncontrollably.
His eyes, the only part he could still command, were filled with disbelief and confusion. Why had he fallen for this? Was it ninjutsu? Genjutsu? Where was the caster?
As his body trembled while walking, he could feel his will clashing against this forceful control.
But the struggle ended with him kneeling on one knee before her.
"A Jonin?" Her lofty tone sounded more like a statement than a question.
The woman seated above extended a hand and made a gesture.
After that motion, Shirakumaru's trembling body went still. His consciousness felt as though it were trapped in an isolated prison, watching everything unfold but unable to act.
As darkness fully descended upon him, the last thing he heard was the woman's cold voice echoing in his mind:
"This one can be used. Dispose of the others."