"First, cooling..."
Jin had begun developing new weaponry alongside Laojun. Elsa was also present, acting as his assistant.
"The goal is to strip away thermal energy."
"Convection, conduction, and radiation, I believe," Laojun replied.
"Exactly. However, I’m thinking we should start by analyzing the Ice-type magic, Ice."
Ice magic produced phenomena that could not be explained by thermodynamics alone.
"Elsa, could you try using Snow Bullet outside for a moment?"
"Mm, understood."
Jin went outside the laboratory with Elsa and began his analysis of the magic.
"...Snow Bullet."
Snow manifested at Elsa’s hand and shot forward at a considerable speed. Jin used the magic Trace to investigate the spell's composition.
"Hmm. As I thought, the basis is Cooling."
Cooling was a spell from Craft Magic, typically used to cool down components that had overheated during production.
"The objective is to clarify its core principles, modify the activation method, and see how far we can lower the temperature."
With Reiko's assistance, Jin and Elsa spent time analyzing the Cooling magic.
"...It isn't convection, conduction, or radiation. The heat is simply being stripped away."
The sight of a high-temperature object cooling instantly was truly magical.
"I can only assume that the thermal energy is being transferred to another space or dimension..."
Having formed this hypothesis, Jin proceeded to modify the Cooling magi-formula.
"Jin-nii, is such a method... possible?"
Watching from the side, Elsa's eyes widened in surprise.
"Yeah. Most likely, this magi-formula is the key. You can't modify magic if you stay trapped by common sense."
"I understand. Jin-nii, you've always been that way."
After much trial and error, Jin finally completed his 'Super-Cooling Magic.' He named it Absolute Zero.
In all likelihood, it was a spell that instantly transferred a target's thermal energy into another dimension. By adjusting the intensity, it was capable of cooling objects from extreme temperatures near absolute zero down to just below freezing. However, the mana consumption was extraordinary.
If Elsa were to use it even once, her mana would likely be almost entirely depleted. It seemed the spell would have to be cast via a magic tool.
＊ ＊ ＊
Laojun was using his mobile terminal, Laozi, to manufacture Plasma Swords.
The primary issues were strength and durability. The makeshift Plasma Swords based on the Masamune and Muramasa that Jin had modified had achieved their power by pouring in more than five hundred times the mana required for their original purpose.
"We must reinforce the magi-circuits. And address the cooling."
Since the plasma reached one billion degrees, even if it was contained within a super-strong barrier, the effect of that heat on the sword's body was not negligible. If one held it for too long, it would become more than just uncomfortably hot.
"Fortunately, My Lord has just developed the Absolute Zero magic."
With this, they would likely be able to vent the excess heat. The only remaining issue was the extreme mana consumption, but they planned to handle that by using high-quality magi-crystals and installing high-efficiency ether converters.
No matter how much mana it consumed, it was nowhere near Reiko's one hundred percent output—it required roughly forty percent of her capacity.
Scaling the weapon up for use by the Titans was relatively simple.
"Along with the vibration swords, let us make these the standard armament for Hourai Island's forces."
Laojun immediately began mass production.
＊ ＊ ＊
"I'm thinking of making a barrier bomb."
Jin, having finished the development of Absolute Zero, suddenly made the announcement.
"A barrier bomb, Father?" Reiko asked. Elsa remained silent, listening intently.
"Yeah. The concept is simple. I’ll deploy a barrier around the target and then shrink it."
"...Does that mean... it'll be crushed?" Elsa asked, her face clouding slightly at the thought.
"Probably."
Jin inscribed a magi-formula to create a barrier onto a magi-crystal, along with a magi-formula to shrink it. Finally, he set the spell to be activated by a specific mana signature. The prototype was finished in just ten minutes.
"Alright, let's test it."
Jin stepped outside the laboratory and had a piece of a Gigant Peeder's shell prepared. He threw the prototype barrier bomb at the shell.
"Wake up."
At the keyword, the barrier manifested, enveloping the shell and a portion of the ground. It began to shrink before their eyes. With a grinding, creaking sound, the shell began to buckle.
The spherical barrier, which had initially been about five meters in diameter, was soon less than one meter across. It continued to contract. When it reached a diameter of about thirty centimeters, the barrier bomb itself was destroyed by the tremendous pressure generated inside, causing the barrier to vanish.
What remained was the rounded, hardened shell of the Gigant Peeder. Judging by the way it had sunk into the ground under its own weight, it was remarkably heavy. Assuming the original weight hadn't changed, its density must have increased by more than fifty times.
"Reiko, try to see if you can cut it with Touka."
"Yes, Father."
Reiko brought out her dedicated weapon, Touka, from the laboratory.
"Here I go."
She raised the sword and struck. A dull metallic clang echoed, but the blade did not bite into the material even a single millimeter.
"Alright, try again in vibration sword mode."
"Yes."
The result was the same. Or rather, the blade of Touka had actually chipped.
"Stop!...That's incredible. Have I created a material stronger than magi-adamantite?"
In addition to the successful test of the barrier bomb, Jin had inadvertently created an extraordinary new material.
"Analyze... I thought so."
"Jin-nii, what did you find out?"
"...The molecular structure has been compressed."
"Eh?"
Under normal circumstances, this would be unthinkable, but the Gigant Peeder shell—being a material that possessed mana—had stabilized in its compressed state without collapsing.
"Is it the work of the free ether? If so, this might be applicable to magi-adamantite as well."
Jin created another, even more powerful barrier bomb and prepared a block of magi-adamantite measuring about one cubic meter. It weighed 19.3 tons; at this weight, no one but Daidara or Reiko could move it.
Jin threw the barrier bomb and activated it. This time, a spherical barrier about two meters in diameter appeared and began to contract. When it reached about sixty centimeters, the barrier bomb collapsed, and the barrier vanished.
What remained was the magi-adamantite, compressed to a sphere nearly sixty centimeters in diameter. Its density had increased tenfold.
It was a sphere roughly the size of a person's embrace, yet it weighed nearly twenty tons. Its specific gravity was approximately 200. To put it in perspective, a sphere the size of a baseball made of this material would weigh over forty kilograms.
"This is amazing..."
It wasn't just the weight; the hardness was also incredible.
"I'll call it hyper-adamantite! I'll use this to repair Touka!"
Seeing the new material, Jin grew as excited as a child. Elsa watched him with a look of curiosity.
If he made the entire blade out of hyper-adamantite, it would be too heavy to use. Therefore, following the construction of a Japanese katana, he used the new material for the edge and sandwiched it between layers of original magi-adamantite to keep the weight in check.
Naturally, the vibration sword mode was kept. Since the base was magi-adamantite, it could be further reinforced by channeling mana through it.
"Alright, Reiko. Try cutting the remaining hyper-adamantite with this."
"Yes, Father."
Touka was now about three times its original weight. After reinforcing it with mana, Reiko swung it effortlessly and struck the ingot of hyper-adamantite.
With a clear, high-pitched metallic ring, the ingot was sliced perfectly in two. This was the level of sharpness achieved through mana reinforcement alone, without even activating the vibration sword mode.
"Incredible... It's become the ultimate sword."
"Thank you very much, Father."
Reiko had been looking downcast when she chipped Touka's blade earlier, but now she wore a joyful smile.
＊ ＊ ＊
"Hyper-adamantite, I see. As expected of My Lord. I shall use some of this to reinforce the unit investigating the depths of Inado Mine."
Laojun had been curious about the mysterious magi-device located deep within the mine. A few days later, he would develop a boring machine for subterranean exploration.
Thus, the development of new weapons and materials progressed, and the military power of Hourai Island reached even greater heights.