Because they would be cooperating with Konoha later, Ryuji proceeded with extreme caution when extracting samples from the two, careful not to leave any traces on them.
He only performed physical exams, drew blood, ran tests, and checked for differences in their constitutions compared to ordinary people while they were still unconscious.
But after a series of checks, finding they were no different from ordinary people, he lost interest.
He simply collected their samples properly in case they were needed later.
After completing all this, it was already dark.
Ryuji chatted with Sara, who came to discuss matters, answering questions and giving instructions for a while, then went to rest.
…
The next day.
Early in the morning, Ryuji entered the production facility to modify the production equipment and the Dragon Vein channel.
He needed to complete the preparatory work for building the Mechanical City before going to Konoha. That way, when he left for Konoha, the personnel sent by the Third Kazekage could continue the work.
First, build an additional production line for worker puppets. Second, modify the original production line for knight puppets to produce Mechanical City's parts and smelting materials.
Due to funding issues, the construction schedule was significantly slower than planned, so Ryuji didn't expand the production facilities much.
The main focus was increasing the Dragon Vein channels.
Ryuji divided the Dragon Vein into two major zones: one for supplying the production equipment's needs, the other for supplying the puppets' needs.
Then, based on the patrol areas of the puppets and the planned construction area of the Mechanical City, he delineated one hundred and thirty channels.
This was temporary. Once the Mechanical City was built, changes would be needed, redistributing based on the city's zones.
Finally, regarding the Dragon Vein's security... To prevent enemies or spies from infiltrating and causing havoc at the Dragon Vein site during construction, leading to a Dragon Vein rampage, Ryuji designed three spiral checkpoints named 'Gate of Life and Death' above the Dragon Vein.
These were Tai Chi gates made from an alloy mixed with secondary Adamantium, Vibranium, and Chakra Metal, using a spiral gear principle.
The structure was bidirectional, shaped like a disc slightly convex upwards, resembling an enlarged round shield.
Dragon Vein Chakra could pass through automatically-closing filter ports at the center of each gate.
Additionally, each gate had an artificial soul serving as an identifier, autonomously recognizing identity. Only puppets containing Ryuji's soul consciousness could bring people in or out.
Ryuji planned to dismantle the existing spiral staircase for entry and exit, then specially produce flying puppets responsible for transporting people in and out.
This way, the hundreds or thousands of meters of altitude would serve as another checkpoint.
Enemies wanting to reach the Gates of Life and Death would need parachuting equipment and then have to violently break through three gates.
But gates made from Adamantium and Vibranium materials, with a structure based on Captain America's shield... currently, no one in the Shinobi World could violently break through them.
However, before building this defense system, he needed a control system to regulate the Dragon Vein's output.
Otherwise, having to come here for every issue would easily create opportunities for enemy infiltration.
Of course, this was also a major project. One person couldn't complete it in a short time.
Therefore, Ryuji prioritized building the production equipment for worker puppets.
Then, using Dragon Vein Chakra to start production, creating worker puppets to work together would undoubtedly save the most time.
…
Time passed gradually.
On the first day, at 9 PM, Ryuji completed the production line for worker puppets.
On the second day, hundreds of worker puppets were produced.
These worker puppets could fold their bodies 180 degrees. Their upper and lower body joints, heads, arms, etc., could rotate 360 degrees. Their forearms and hands could retract and be replaced with screwdrivers, hammers, saws... and various other tools.
Simultaneously, thrusters were installed on their backs, enabling flight.
They could operate in any environment except underwater.
On the third day, Ryuji finished modifying and expanding the production equipment.
On the fourth day, the construction team sent by the Third Kazekage arrived.
Over three hundred people in total. Among them, over fifty were puppeteers; the remaining two hundred and fifty were skilled craftsmen from the village.
The team leader was Ebizo.
As Chiyo's younger brother, Ebizo was also a puppeteer, proficient in mechanical arts and architecture.
In fact, due to the application fields of mechanical arts, every puppeteer had some expertise in architecture.
Perhaps their perspective was limited by the era, but their skill level was no worse than professional engineers from Ryuji's previous life.
After explaining the construction schedule and plans to Ebizo, Ryuji began improving the Dragon Vein channels.
Meanwhile, Ebizo started communicating with Sara and hosted a party in the evening to celebrate the integration of the people of Roran into Sunagakure.
During the banquet, whether pre-arranged by Ebizo or because the Sunagakure's villagers truly didn't mind outsiders joining, men drank and ate meat together, and single men and women invited each other to dance around the bonfire.
In short, the atmosphere was harmonious.
The previously noticeable sense of estrangement between the two sides diminished significantly.
On the fifth day, Ebizo arranged for trusted individuals to buy materials from other cities and countries. He himself led the construction team and worker puppets to prepare for the Gates of Life and Death.
Sara proactively brought a group of young adults to help.
Participating in construction together would help the people of Roran integrate better into Sunagakure. Ryuji didn't refuse, assigning them tasks they could handle and calculating wages.
On the sixth day, the worker puppets produced thirteen hundred units, but the materials left by Anrokuzan were exhausted.
Considering the construction schedule, Ryuji decided not to buy more materials for production for now.
Ryuji himself continued modifying the Dragon Vein channels.
This was skilled work, somewhat time-consuming.
On the eleventh day, Ryuji finished modifying the Dragon Vein channels.
The one hundred and thirty channels were aligned with the machinery to be deployed for work in the future.
On the twelfth day, Ryuji led the construction of the Gates of Life and Death.
On the fifteenth day, the people sent to buy materials returned, bringing back large quantities of various ores.
The modified metal smelting furnace officially started operation.
On the seventeenth day, Sunagakure's second batch of logistics personnel arrived, bringing a large number of modern construction machines.
Things like cranes, excavators, and similar equipment.
These items were made by having Aka use the 3D Printer to produce parts, which were then transported outside via scrolls for assembly, then placed back into scrolls for the logistics team to bring over.
With these machines assisting, the construction progress accelerated several times over.
The foundation for the Gates of Life and Death was laid.
Ryuji had Ebizo lead the personnel, machines, and one thousand worker puppets to start digging the foundation, preparing for the official city construction.
Simultaneously, the factory began producing the first part of the Mechanical City: the Ugo Ring.
This was an item recorded in the alchemy section of the 'Book of Raziel' from a certain Arabian parallel mythological world.
Burying it in the earth could solidify the ley lines, preventing the earth's energy from leaking, making it eternal and indestructible.
Its effect was to maintain the earth's vitality and preserve its thick, solid characteristics, never drying up or breaking.
Of course, phrases like 'never leaking' and 'eternal and indestructible' were embellishments in the book. How long it could actually last depended on the materials.
And the material Ryuji prepared was the 'Philosopher's Stone'.