The magic-frame style golem.
This was one of the things Jin—currently operating under the name of the Third Generation—wanted to leave behind as a gift to this era.
He knew of many techniques that people had worked desperately to develop and preserve, only for them to be lost to the passage of time. He felt that his role from now on was to ensure such technologies were passed down.
"It seems the magi-resin we can harvest from around here has more than enough performance for our needs."
This was the result of an analysis conducted after Jin had sent the Smiths to collect Pinacea sap from the forest far to the north of Kaina Village.
The tree contained the alkaloid atropine. On Earth, this was most commonly found in Solanaceae plants like nightshade, but here on Ars, it was somehow present in the bark and sap of the Pinacea, a member of the pine family.
"Keep the isolated atropine in storage as well," Jin instructed.
Atropine inhibited the parasympathetic nervous system and was used as a pharmaceutical. Jin recalled that United States military regulations even dictated its use for those exposed to nerve gas.
However, since current medical handling was difficult for him, he simply intended to keep it in stock for the time being.
"If Elsa were here, she could have put this to very good use. Saki, too, would have been delighted to research its properties."
Jin found himself momentarily lost in thought, reminiscing about his former beloved wife and his old comrades.
Setting those feelings aside, Jin decided to pause Freddie's intensive training and have him observe the golem construction process instead.
"We've gathered enough magi-resin to build at least one unit, so that's settled. For the skeleton, we'll use light silver."
The overall design followed the Adriana-style—in other words, body lines that closely resembled a human's.
"Light silver should be sufficient for the exterior as well, wouldn't you say?" Marikka suggested.
Choosing ordinary light silver instead of 64 light silver was a silent message to the engineers of the Kingdom of Elias: "Study this, and use it as a reference to create even better golems."
To that end, he even decided to de-tune the magi-resin by mixing the Pinacea-derived version with magi-pine resin in a fifty-fifty ratio.
Even with these concessions, the golem would possess reaction speeds and output that the standard models of this era could never hope to match.
"As for the type... perhaps a female-type?"
Jin was about to suggest a lady's maid golem when a voice interrupted him via his communication link.
"No, My Lord. The New King is quite the martial arts enthusiast; he prefers physical prowess over magic. A male-type would be far more appropriate."
"Oh, is that so, Laojun?"
If the king encouraged martial arts despite his kingdom's history with the Magic Federation, Jin knew exactly how to build it. He instantly visualized the blueprints in his mind.
"Alright."
Just as he was about to begin the construction, he remembered that this project was also a training exercise for Freddie.
"The plan is set. First, we start with the blueprints."
Blueprints were indispensable for mass production. They required a general assembly drawing, detailed assembly drawings, part drawings, and a bill of materials. For a project of this scale, the total count could easily reach into the hundreds.
One could only build something from a single assembly drawing if the object consisted of only a few parts. But if a full set of drawings was prepared, anyone capable of reading them could replicate the same quality and design.
It was an essential element of large-scale manufacturing. Jin felt once again that he should focus on establishing these standards in this era. Thus, while he usually relied on his mental blueprints, he decided to properly document everything this time.
He did have a magi-device designed for this exact purpose: the magi-plotter created by his predecessor four hundred years ago.
By donning a headset similar to the one used for controlling a Doppel, Jin could project his thoughts onto a magi-screen. These thoughts were then refined into technical drawings. Because the display on the magi-screen could be modified at will, he could tweak the design until he was perfectly satisfied before outputting the final product.
It was called a plotter rather than a printer because it used a mechanical arm, adapted from a Golem arm, to physically draw the lines.
A drawing roughly the size of an A3 sheet could be finished in about three minutes, depending on its complexity. Using this tool, Jin first produced the external three-view drawings.
While Marikka, Rubina, and Greena already knew how to read drawings made with third-angle projection, Freddie did not. Jin had to start with the basics.
"...And so, this is the front view, this is the side view, and this is the top view. If necessary, we also draw bottom or rear views."
"I see! I can definitely understand the overall shape when it's laid out like this!"
Even without prior knowledge of engineering standards, Freddie's spatial awareness was naturally high. He mastered the concept of the drawings almost immediately.
"The height will be 180 centimeters, with a build slightly leaner than average. Does that sound right?"
"Jin-sama, is there a specific reason for making him 'slightly leaner'?" Freddie asked, trying to grasp Jin's intent.
"Yes. It's a personal theory of mine, but I believe that a true master of 'technique' must be agile."
Technique versus Power. Softness versus Hardness.
"There's a saying: 'Softness overcomes hardness.' There is a certain beauty in overwhelming an opponent with pure skill."
Of course, the reverse—"Hardness overcomes softness"—was also a valid philosophy, but Jin had his preferences.
"That's a funny thing to hear from Jin-sama, considering how much you dote on Reiko-chan," Rubina remarked with a cheeky grin.
"...Reiko has incredible technique as well, despite her appearance. She just... rarely has an opponent that requires her to use it."
Jin offered a defense that even he felt was a bit weak.
"...Anyway, we're getting off track. In my mind, a master of martial arts has a lean, tight physique, not bulging muscles."
"I think I understand that," Marikka agreed.
"Thanks, Marikka. So, we'll proceed with that body type."
Since no one else objected, Jin moved to the next step.
"Now then, let's design the skeleton."
Because this was a magic-frame style build, the skeleton would essentially be a single, integrated piece.
"Freddie, I know you have questions, but first, I want you to understand the nature of this frame."
"Y-yes, sir!"
"You're probably wondering how it moves. To put it simply, we use the Forming magi-craft to bend the joint sections."
"I see..."
"We'll build up the body with magi-resin, but before that, we need to prepare the shield case to house the magi-devices."
Jin explained that the shield case was designed to block external magical interference.
"We house the shield case in the chest, and inside that, we place the magi-devices, starting with the control core."
Jin continued to explain how different golems could be equipped with various magi-devices to give them specialized functions.
"Why the chest and not the head?" Freddie asked.
"Good question. Greena, can you explain why?" Jin passed the question to her.
"Oh! Um, yes! Because the head is a protrusion, its defensive capability is naturally lower. We house the core in the chest because that's where we can make the armor the sturdiest."
Though startled by the sudden prompt, Greena answered clearly. Jin nodded in approval.
"Exactly. Now, there's one more area where our configuration differs from a human. Rubina, do you know what it is?"
"Yes! It's the tactile sense. While humans have sensory organs scattered all over their skin, golems usually only have tactile sensors in a few specific locations."
Expecting the question to come her way, Rubina answered confidently.
"Very good. Marikka, anything to add?"
"Yes. U-um, you shee... as I wash shaying, while we call it a 'tactile sense,' golems that actually possess it are extremely rare. To be precise, they're only found in those made by Jin-sama or his direct lineage."
"That's right."
Even Adriana Barbora Tsetse had never succeeded in giving her automata a true tactile sense. Her creations relied on high-speed feedback and analytical power—hundreds of times faster than a human's—to handle eggs without breaking them or hold slippery adamantite.
The first to be equipped with a true tactile sensor was the automaton Aaru, which Jin had given to his friend Saki. Since then, Jin had given tactile senses to everyone on Hourai Island, starting with Reiko, as well as the golems and automata of his companions.
"An ordinary golem recognizes an object, calculates how much force it should use, and then applies that force. Because it lacks real-time sensory feedback, it can sometimes accidentally crush a glass if its calculation is even slightly off."
"...I think I'm starting to get it."
Freddie seemed to grasp the concept, even if the finer details were still a bit blurry.
And so, Jin's lecture continued, weaving theory into the practical work of creation.