"Now then, where should I begin?"
Having returned to Hourai Island after seeing Reinhard off, Jin already had a general idea of his future course of action.
His plan was to "intervene without revealing his identity."
It was a classic trope from superhero stories, where the hero's true identity remains a secret until the very final episode.
Jin figured that since he had already crafted a helmet and a reinforced suit, the timing was perfect. Then the idea of a giant robot had occurred to him. There was no way a man like Jin could resist such a project.
"I can't directly intervene in the war, but..."
He felt it might be acceptable to step in if ordinary civilians were ever in grave danger. Furthermore, he believed a giant robot would be the ultimate symbol to brandish against the Unifilar.
They were, if nothing else, conspicuous.
He suspected that because people couldn't comprehend what was happening when targeted by lasers or railguns, those weapons didn't instill quite the same level of visceral dread.
"A giant robot... If it's a golem, the sheer presence should be enough to intimidate anyone."
With his goal set, he started by developing the necessary materials. If he built it out of adamantite, the weight would be astronomical, so he decided to use light silver as the base.
"Hmm, I recall learning that titanium is usually alloyed with things like aluminum, vanadium, or molybdenum..."
Jin desperately ransacked his memories for technical knowledge from his previous life. He surmised that light silver was essentially titanium where the neutrons had been replaced by magitrons. If that were the case, he reasoned it should possess properties similar to titanium.
"I'll just have to experiment."
With Reiko acting as his assistant, Jin began his search for the perfect light silver alloy. Thanks to his Craft Magic, creating test pieces took only a few seconds. It was a massive advantage. By the end of the morning, he had discovered an optimal combination of metals.
"Welcome back, Jin-nii."
As was becoming custom, he had lunch with Elsa and the others. Since it was a cloudy day, they ate indoors. Jin looked at the somewhat clumsily sliced Persica fruit on the table.
"Oh, did you peel the Persica today, Elsa?"
Elsa offered a small smile, pleased that he had noticed. The menu consisted of freshly baked bread, citran marmalade, vegetable salad, vegetable soup, and Te-e tea. Every dish bore the subtle hallmarks of Elsa's seasoning.
"You're getting better at this every day, Elsa," Jin praised her between bites.
"I'm happy to hear you say that, Jin-nii."
Elsa smiled brightly at the compliment.
After lunch, Jin returned to testing his new alloy.
"Let's see... light silver ninety, aluminum six, vanadium four."
In the end, he settled on a composition known as 64 alloy. Aluminum, which had been synonymous with the word "light silver" back on Earth, seemed to be even rarer than titanium in this world.
Vanadium had an atomic number of 23, placing it right after titanium and before chromium, so Jin had managed to identify it by performing a detailed Analyze on various samples. It existed in small quantities within the soil here, and he had even found it piled in a corner of his warehouse labeled as a "mysterious ore."
The Predecessor had shown remarkable foresight in ordering that such unknown ores and metals never be discarded.
Putting that thought aside, Jin produced the light silver 64 alloy and then diffused mithril silver into the mixture. This added a magical bond to the interatomic forces, ultimately allowing him to increase the material's strength to seven times that of standard light silver. It was a staggering achievement.
"I should probably use this alloy for everything involving light silver from now on," Jin remarked, impressed by his own creation.
Now that the material was finalized, it was time to move on to construction. He recalled Smith golems 91 through 100 to serve as his assistants. Normally, they would be building an aircraft carrier under Laojun's direction, but Jin wasn't particularly concerned. Laojun, for his part, understood Jin's occasional bouts of whimsical engineering all too well. After all, the vast majority of Laojun's knowledge had come directly from Jin.
"I think I'll try making three units: an autonomous type, a remote-controlled type, and a manned type I can pilot myself."
The giant robots Jin knew generally fell into three categories: those controlled by a remote, those with a degree of sentient will, and those piloted from a cockpit in the head or chest.
The basic structure for all three would be identical. They would share the same skeleton, musculature, and exterior plating. Since they were fundamentally just larger versions of the golems he had built before, Jin managed to complete the prototypes in just one hour with the help of Reiko and the Smith golems.
Next came the installation of the control systems. The autonomous type was almost identical to a standard golem, making it easy to finish. He designed it to receive orders via a manacam.
"Alright. Titan 1, move!"
He had named it "Titan" as a play on its primary material, titanium, and the giants of Greek mythology. Titan 1 stood up in the plaza before the laboratory. It was a truly imposing sight.
"Good. Now, try walking."
Since he hadn't installed a vocalization mechanism for the test, Titan 1 moved in total silence. However, its footsteps were heavy and sure. The way the ground trembled beneath its weight was incredibly powerful.
"Excellent. Now, try running."
Following the command, Titan 1 began a slow jog, gradually picking up speed. Its movements were fluid and natural.
"Reiko, what's your assessment?" Jin asked, wanting her perspective.
"It is quite good, Father. It cannot even be compared to the Gigas we fought previously."
"Yeah, you're right about that."
True to its autonomous nature, Titan 1 reached the edge of the plaza and turned back on its own.
"Okay, let's see some shadowboxing."
Because Jin had transferred some of his own martial knowledge into its core, the golem understood and began to move. Its agility was shocking for its size. Jin beamed, seeing his hypotheses proven correct.
"Titan 1, stand still."
Jin halted the machine to check for any strain or malfunctions. His face was lit with excitement.
"Yes, it looks perfect. Even after that activity, the joints, skeleton, and muscles are all fine. I think we can call this a success!"
"Congratulations, Father. It is truly magnificent," Reiko said, sharing in his joy.
"Thanks. In that case, let's finish the manned type next!"
Swept up in his enthusiasm, Jin threw himself into finishing Titan 2. He decided against placing the cockpit in the head for safety reasons, opting for the torso instead. To ensure the pilot wouldn't have to handle every minor movement, he copied the movement data from Titan 1 into a control core to handle balance and stabilization. The pilot would simply provide directional and action inputs. Jin knew better than to think he could master piloting a giant robot from scratch.
Consequently, Titan 2 was finished relatively quickly. Since there was no danger of falling out of the sky, Jin decided to climb in immediately.
"Father, are you sure about this?"
"Yeah. It's just like driving a car."
Jin didn't actually have a driver's license, but he had operated forklifts and other machinery on factory grounds back in Japan.
"Alright, here goes."
Jin sat in the cockpit located in the chest cavity. Since it was still a prototype, he hadn't attached the chest armor yet, giving him a clear view of the plaza.
"Go!"
As he depressed the accelerator, the output of the ether converter and mana driver spiked. Titan 2 began to move in response. At first, it took heavy, lumbering strides that slowly grew faster. He made a wide U-turn at the edge of the plaza and headed back—only to come to a sudden, jarring halt.
"...Father?"
Reiko, who had been running alongside the machine, looked up to see Jin's face had gone pale. She knew that look all too well. She leaped into the cockpit instantly.
"Heal <Verheilen>!"
She chanted the Shouro-style incantation to soothe his condition.
"A-Ah... thanks, Reiko. You're a lifesaver."
Jin looked utterly haggard.
"I got motion sick in seconds..."
Because the machine was nearly ten times larger than a human, the vertical swaying during its gait was also amplified tenfold. The physical toll on the pilot was immense, and Jin's equilibrium had surrendered almost immediately.
"Regrettably, the manned type is a bust for me."
Jin climbed down from Titan 2 with Reiko's assistance.
"I believe I would be fine, Father," Reiko offered helpfully.
Jin nodded. "True. I'll finish this one up as a dedicated unit for you, then."
Deciding to finalize that later, he moved on to the third and final unit: the remote-controlled Titan 3. This one utilized the same system as the body double he had crafted recently. He would sit in a specialized cockpit that projected images from the magic eyes installed in the golem's head. He chose this method partly because it was the only way to operate the machine at a distance, and partly because he still wanted to experience the thrill of "piloting" a giant robot without the vomiting.
Jin worked through the evening, fueled by a passion that only a magi craft meister could possess. By the time the sun set, all three machines were complete.
The giant robots were finally finished.