Apart from these minor surprises that are merely considered 'good', upon completing the third and fifth-year check-ins, he also received grand prizes no less significant than the beginner's reward.
It was precisely because of these two grand prizes that Ryuji gained the confidence, as a mere mortal in this world filled with determinism and bloodline theory, to stand shoulder-to-shoulder with gods.
[Ding! Check-in successful. Reward obtained: 10 experience points.]
After hearing the system prompt in his mind, Ryuji glanced casually at the changes on the panel data before focusing on his meal.
He had long grown accustomed to these insignificant rewards.
"Finished eating." Ryuji put down his bowl and chopsticks and instructed, "Aka, I'm going to the underground workshop. Notify me if anyone comes."
"Understood, Master."
Ryuji nodded, stood up, and headed for the underground workshop.
The workshop wasn't large, about 60 square meters.
Materials were piled in the corners, half-finished or discarded puppets were placed along the sides, and in the central open area were processing tools.
Most were hand tools like chisels, small hammers, carving knives, saws... There were also one or two mechanical lathes for processing parts leaning against the wall.
Ryuji walked to the center of the room and formed hand seals.
Clack, clack, clack...
The sound of mechanisms operating echoed in the room. The floor in the center automatically opened, revealing a dark passageway leading to a lower level.
Ryuji glanced around. Seeing nothing unusual, he stepped directly into the passage.
Clack, clack, clack...
The mechanism sounds rang out again as the floor automatically closed.
Using a flashlight, Ryuji walked down a long staircase in the dark passageway, finally arriving at another space.
This was also a workshop, spacious and bright, filled with various impressive-looking equipment and instruments, giving one the feeling of being in the future.
Ryuji walked to the innermost instrument.
It was a console with a basketball-sized crystal ball floating above it.
Ryuji took out a scroll, placed the Third Kazekage human puppet on the console, and said, "Help me analyze this puppet."
Immediately, the crystal ball lit up.
A beam of light shone from within, enveloping the human puppet.
Dense data appeared in the crystal ball, flashing by too quickly to discern what it was.
After about an hour, the crystal ball stopped flickering, displaying clear data.
Name, weight, size, structure, principles, materials used... All the secrets of this puppet were revealed.
"Let me see the principles."
As he spoke, the data in the crystal ball transformed, enlarging the principles section to fill the entire crystal ball.
[The corpse's life force is preserved using Chakra. Limbs are severed, the abdomen hollowed out, replaced with mechanical prosthetics to retain the body's original abilities while possessing mechanical power.]
"So it's just a living corpse with many prosthetics? Tsk, it really is achieved through prosthetic principles!"
So-called prosthetics aren't just limbs.
Heart, stomach, liver... These internal organs can also be replaced by machines.
In the real world, hospitals already have mature technology for replacing damaged organs with mechanical ones to treat patients.
However, the intricacy of the human body is unmatched by any machine.
No matter how precise or high-density those mechanical organs are, their functionality cannot compare to the original organs.
Therefore, people who undergo mechanical organ replacement surgery experience a decline in physical functions.
But they are still complete humans, possessing all human functions.
Sasori's human puppets are made using this principle.
Although human puppets are modified from corpses, they still possess everything human. Using puppet techniques to move the puppet allows it to utilize the abilities the corpse had in life.
But as said before, the intricacy of the human body is unmatched by any machine.
Therefore, human puppets, with most of their bodies replaced by machinery, retain only a small portion of their original abilities.
This sounds very unscientific.
But this world itself is unscientific.
The difficulty of human puppets lies not in the modification but in preserving the corpse's life force.
After death, life force dissipates.
Keeping a corpse's life force active... For the science of his previous world, this would be an impossible task.
But in this world, while difficult, it is not impossible.
— Yang Release.
There are seven Chakra Natures in this world.
Aside from the commonly used Wind, Fire, Water, Earth, and Lightning, there are also Yin and Yang Natures.
Yin Release, sourced from Spiritual Energy governing imagination, creates form from nothingness. Yang Release, sourced from Physical Energy governing life, grants life to form.
The Sage of the Six Paths skillfully used these two abilities to develop the creation technique 'Yin-Yang Release'.
Later generations, though unable to use these two abilities to the extent of creating all things, could still apply them separately in basic ways.
For example, some basic Genjutsu or Medical Ninjutsu belong to applications of Yin and Yang Release.
Injecting life force into a dead corpse to keep it perpetually active is not a difficult task.
"Aside from lacking a soul, the lie I made up at the round table meeting is actually true." Ryuji marveled.
"However, I'm not here to study human puppets. Use the flesh and blood parts of the Third Kazekage as a blueprint to deduce his complete body."
As he spoke, the data in the crystal ball flickered again.
This crystal ball is called the Observation Device.
It was Ryuji's third grand prize.
It is bound to Ryuji's brain, using the knowledge in his mind to analyze and deduce things.
The more complex the object being analyzed or the problem being calculated, the slower the speed and the longer the time required.
The complexity of objects and problems depends entirely on Ryuji's understanding of them and how helpful the knowledge in his mind is for analyzing or deducing them.
Of course, because it is bound to his brain, the conclusions reached by the Observation Device also directly appear in Ryuji's mind.
However, receiving too much information at once places a severe burden on the brain.
So Ryuji disabled this function, planning to re-enable it after his brain became strong enough to ignore this issue.
As for understanding of the human body and puppets... Ryuji, possessing all of Touko's knowledge and having thoroughly studied many famous books from other worlds on mechanical engineering and human body engineering, is absolutely a master among masters.
Therefore, the Observation Device quickly deduced the data model of the Third Kazekage's complete body.
Facial features, height, weight, facial characteristics, body fat percentage, muscle density, bone flexibility and strength... The crystal ball displayed a human data model of the Third Kazekage, with dense data listed around it.
Ryuji memorized the data and walked toward another machine opposite.
This was a computer, connected to a console beside it. The console had many light pen mechanical arms.
On the other side of the console, it was linked to a sealed box, with only a basketball-sized opening on top that could be freely closed.