Bringing the giant golem to the surface allowed the analysis and repairs to proceed smoothly.
Scaffolding was erected around the massive frame, and engineers swarmed over it to begin their work. Following Jin's suggestion, the team used sandworm skin for the artificial muscles. He assured them it would be capable of producing equal or even greater power than the original materials.
Drafting several young magi engineers for the task, the replacement of the musculature took a full day. Meanwhile, the skeletal frame showed minimal corrosion, allowing that maintenance to wrap up in just half a day.
The exterior required significant labor, but the task itself was straightforward. By enlisting a large number of junior engineers, the team finished the outer casing in another half-day.
The real challenge lay in the internal magi-devices. This was the part of the project Jin found most intriguing.
"Hmm, so this is an ancient artifact's magi-device..."
Jin and the others stood deep in thought before the component that had been removed from the golem's chest.
"What on earth is this?" one engineer asked.
"I've never seen a magi-sequence like this before," another added.
Jin remained silent for a moment. It was an ether converter—a magi-device familiar to both him and Elsa.
(Though its efficiency is quite poor... It doesn't seem to be from the Predecessor's lineage.)
"The magi-formula here likely acts upon the free ether," Jin remarked casually.
"Umu. If that's the case... I see! If it collects the surrounding ether, it must be to convert it into mana!"
Jin subtly steered their logic, ensuring they reached the correct conclusions while he remained strictly in a supporting role.
Elsa, for her part, observed the Magi Engineer Maestro, Gebalt, and measured her own abilities against his.
(I'm nowhere near Jin-nii. Not in knowledge, comprehension, or the way he uses mana.)
Taught by Jin and blessed with innate talent, Elsa already surpassed the current Magi Engineer Maestro in terms of knowledge and technical skill, though she lacked his years of experience.
On the other hand, Marcus Greenbalt remained silent, rarely speaking. As the grandson of the previous Magi Engineer Maestro, Sigmund Greenbalt, he had received an elite education from a young age, but he harbored a slight inferiority complex for having fallen just short of the skills required for the title himself.
Even though he had been manipulated by the demon Marcosius, Marcus had mastered the construction of the massive Golias units. That achievement had earned him a place on this artifact restoration project. He had been thrilled, believing his path to becoming a Magi Engineer Maestro was finally clear—until Jin Nidou appeared. Jin had arrived with Reiko, the automata who had effortlessly crushed Marcus’s Golias units.
It was no wonder Marcus felt stifled. Even the task of hoisting the giant golem with his Golias units likely would have failed without Jin's guidance, a fact that did nothing to brighten his mood.
Unconcerned with individual motives, the analysis proceeded slowly. Had Jin done it alone, it would have been finished long ago, but neither he nor Elsa were so thoughtless as to say that aloud. Rather, they were keen on observing the technical level of an average magi engineer.
"...Regarding the control core, what exactly is this?"
"I wonder," Jin replied.
Even Jin had never seen a core quite like this. Or rather, he knew of something similar.
(Could it be a remote-control device...?)
It shared slight commonalities with the ones he used in the Titan or his Body Double—specifically, a communication function using mana.
"There's no doubt that this is the control core meant to operate this giant golem," one of the engineers said. "But as it is, there's no way it could move!"
It was neither an autonomous type, a semi-autonomous type, nor a command type. As the group racked their brains, Jin once again offered a hint.
"It has some parts similar to a command type, doesn't it? Like this section here."
"...Hmm, indeed."
"However, even though it has basic operation formulas, the command slot is blank. Instead, it's connected to this magi-device, which is..."
"I see. Does this magi-device issue the commands? No, it shouldn't have such a function."
"What if we considered that it isn't commanded by voice, but by something else?" Jin suggested.
"...As expected of the Magi Craft Meister. That possibility is very high! If so, then this magi-device here must be..."
After spending a full day on the problem, the system was officially dubbed a "remote-control type," adding a new category to the known operation types for golems.
"Jin-nii, what are you thinking about?"
As Jin was relaxing in the room provided for him within the Imperial Palace, Elsa arrived carrying a bottle of wine.
"Hmm? Just about the giant golem we're researching, I guess."
"I see." Sitting across from Jin, Elsa showed him the label. "This is one of Rai-nii's favorite brands. Nashiriine 3450, a noble rot wine."
"Noble rot wine... that's the sweet kind, right?"
Noble rot wine was made from grapes affected by a specific fungus that caused water to evaporate, concentrating the sugar. It resulted in an extremely sweet vintage, often preferred as an aperitif or a dessert wine. Both Reinhard and Elsa were fond of it for dessert.
"Yes. It's smooth, almost like juice."
Elsa had Edgar pour glasses for Jin and herself. Jin took a sip immediately.
"Yeah, it certainly is sweet."
Since Jin wasn't a heavy drinker, he preferred sweet wines over dry ones and found this vintage very much to his liking.
"...So, what is it about the giant golem that's bothering you?" Elsa asked, continuing her questioning while savoring her glass.
"Well, the first thing is settled. I was worried it might have a device built in to trigger an Ether Stampede."
The Ether Stampede that occurred at the end of the Great Magic War had been orchestrated by homunculi known as Negadolls. Driven by a hatred for humanity and the demon race, they had triggered the catastrophe to wipe out both. As a result, the population of the known world had plummeted to less than forty percent.
"...That makes sense."
Fortunately, the artifact left here seemed to have no connection to the Negadolls.
"And the second thing?"
"The control device. Like with the Body Double or Titan 3, there should be a controller or a cockpit somewhere, but it's concerning that we can't find it."
Without that, the giant golem wouldn't be able to move even if the repairs were completed. The work would be meaningless.
"Is that all?"
"No, there's more. The magi-formula that was engraved on the back of the chest armor."
"I didn't see that," Elsa said, looking puzzled.
Jin explained in a soothing tone. "I suppose not. I found it and immediately ordered Reiko to take it to the chancellor, so it's only natural you wouldn't know."
"...Was it something dangerous?"
Jin nodded and took another sip of wine to moisten his throat. "Dangerous in its own way. It was a magi-formula that amplifies magic."
It was a piece of magi-engineering that had been lost to time.
"But you know it, don't you, Jin-nii?"
Jin nodded at Elsa's certain inquiry. "Yeah. But it's full of flaws..."
Seeing the question in her eyes, Jin began to explain with a wry smile. "...The ether concentration in the current world is too thin."
"...Ah, I see."
Elsa understood immediately. She knew that before the Great Magic War, the ether concentration was at least three to five times higher than it was now. In other words, the technology was useless without a vast supply of ether.
"Is it correct to say that even if you amplify it, you'll immediately run out of mana?"
"Exactly. It works similarly to elradrite, though that gives a twenty-fold boost while this is ten-fold at most."
"Still, that's a threat."
A ten-fold increase sounded simple, but in terms of power, a ratio of one to ten was an overwhelming gap.
"I suspect that just moving that massive body consumes a massive amount of mana. They probably needed the amplification function to temporarily compensate for that."
"...If a normal person used this, what would happen?"
Jin frowned at Elsa's worried expression. "...They'd suffer magic depletion immediately."
In this context, "magic depletion" meant the total exhaustion of mana within the body. Even though it was called amplification, it didn't create something from nothing; it merely condensed ten portions of mana into one.
"So, unless you can generate an abundance of mana from a high concentration of free ether, it's a useless technology."
Jin spoke decisively to reassure Elsa, but he knew that, in the wrong hands, it could still be a threat.
(If someone were to treat magi as disposable pawns to launch high-powered attacks...)
However, in the current era where magi were so scarce, it was a tactic that made little sense to execute. Furthermore, Jin felt that if it was managed by the Shouro Empire's Ministry of Magi Technology and kept strictly confidential, there would be nothing to worry about.
"And one more thing..."
"One more thing, what?" Elsa echoed, tilting her head slightly.
"...Regarding the control core, there was a formula written in one part that even I didn't recognize."
Jin's knowledge lacked information regarding the period between the Predecessor's time and the present. He wasn't familiar with every magic tool or magi-technology developed during that gap. While such things were rare, they did exist. Magi-technology had continued to progress incrementally leading up to the Great Magic War.
"If there were no one else around, I might have tried to read it, but..."
There was the risk of showing too much of his own power, the possibility that the contents were better left unknown, and one other major concern.
"There was a high probability that it was protected, so I decided against it."
He had considered the possibility of a trap reacting to any attempt at analysis.
"You mean..."
"Yeah. If it just broke itself, that would be one thing, but if it exploded..."
Jin's own golems were designed with self-destruct mechanisms to prevent forced analysis by others. His concern was far from paranoia.
"I just hope nothing happens because I left that black box alone."
"You could just suggest moving it back underground and lowering the ether concentration again," Elsa suggested. "Then it'll be just like it was before. The risk will be minimal."
"Yeah. I'll propose that tomorrow," Jin replied, the wine beginning to cloud his thoughts with a mild, uneasy fog.