After endless tempering, steel finally obtains the ultimate metal.
The southeastern border of the Metalum Empire.
In that region, once melted and collapsed by the flames of the Ignis Empire, there was now no acrid smoke—only the heavy, weighty sound of hammers filling the air.
The defensive walls that had melted and warped had, before long, been replaced with new metal plates and raised again, and the roofs of the buildings that had burned down were covered with new sheets of metal as well.
The citizens of this city laid iron over the ruins once more.
And they were no longer who they had been before.
Even when their burned exoskeletons were pierced with holes and split with cracks, they reinforced those spots by layering new metal fibers over them.
The iron plates set upon their shoulders were connected as though they were one flesh, and their fingers, hardened by hammering, shone with a brilliance greater than before.
Though they were not formally trained soldiers, the citizens of Metalum seemed to be transforming their bodies into weapons of their own accord.
The sight of people tempering themselves could, of course, be seen among the soldiers as well.
“We must become harder!”
When one steel knight shouted and swung an iron rod, several other knights nearby repeated the same words like a cadence.
“We must become harder!”
The soldiers of Metalum did not fear the flames of Ignis.
Rather, remembering the experience of the damage they had suffered at their hands, they were tempering their bodies so as never to repeat the same mistake again.
There was no need to carry shields in their hands.
Their exoskeletons themselves were shields and defensive walls.
And the steel assemblers were just as busy as the soldiers.
For the assemblers in charge of Metalum’s construction were soon to be thrown into a certain enormous undertaking.
“Our glory is before our eyes. Do not collapse!”
The voice of Crasso, representative of the assemblers, rang out low and deep.
“We must temper ourselves further. For the great modification to come, our strength, our structures, even every last iron plate in this city must all be reinforced.”
The hammering of the assemblers never ceased for even a moment.
From time to time, red sparks flew from their hammers.
Their skill grew more proficient with each passing day.
This was the way all citizens of Metalum lived, and it was their order.
Emperor Oruma, looking down at Oruka, the capital of Metalum, from the edge of the fortress, slowly raised his eyes to the sky.
Perhaps because of the sheen of metal, even the sky looked white.
Until not long ago, dark red smoke rising from the flames of Ignis had filled the sky, but no longer.
Oruma spoke in a low voice.
“There will be no more mistakes. Never again……”
The laboratory beneath the fortress was another place that did not rest.
Immediately after the birth of the Bronze Core, a fusion of the Metal Core and the Life Core, the researchers plunged straight into their next study.
That study concerned the Flame Cores of the Ignis Empire.
Those cores were the ones Terramont of the Terra Empire had seized from Ignis and handed over to Metalum.
“So it is finally complete.”
Researcher Keldren murmured as he looked down at the Metal Core and the Flame Core inside the tank.
The two types of cores seemed already aware of each other’s existence, shaking the space with faint vibrations.
Behind him, Oruma, his retainers, and several researchers watched.
“Are the preparations complete?”
When Oruma asked, Keldren answered.
“Yes. We will begin the fusion.”
After a few operations of the device, the two cores gradually began to draw closer.
In the past, the Metal Core’s structure would have been warped and destroyed by the Flame Core, but now it was different.
The Metal Core was instead accepting the heat of the Flame Core.
Researcher Renma muttered to himself.
“Fire normally melts iron, but this time should be an exception.”
The inside of the laboratory was dyed red.
However, that was not because the fire energy contained within the Flame Core was strong.
It was the color of the newly obtained sheen, as the Metal Core accepted that energy.
Flaaash!
In that instant, a blinding flash exploded inside the tank.
It was a reaction they had never seen while fusing dual-attribute cores until now.
The flash slowly subsided, and soon turned yellow.
“Ohhh……”
Peron exclaimed, as though he had sensed something.
Perhaps the result was exactly what Metalum had wanted so desperately.
As the light settled, only a single core remained inside the tank.
Everyone fixed their gaze on that core.
“It’s a Golden Core……!”
Peron shouted.
The surface of the new core glittered like pure metal, but within it, a heart burning like the sun was pulsing.
The Golden Core created by Metalum.
Gold was not merely a type of metal.
The ultimate metallic substance Metalum had pursued—gold symbolized fruition and authority in itself.
Oruma approached the Golden Core.
He observed the result in detail.
“As expected, our Golden Core is different. Unlike the shoddy thing made by the likes of Ignis.”
Ignis had been the first to create a Golden Core, but their Golden Core had been strongly tinged with red.
However, the Golden Core Metalum had created bore a yellow hue.
In other words, Metalum’s Golden Core was the more refined result.
“This is our true gold. We are the ones who know the true value of gold. The cores of those Ignis bastards are fakes. Their cores are worthless substances that are golden in name alone. At long last, we have brought forth perfect gold!”
Oruma declared on the spot.
Keldren confidently agreed.
“That is correct! Though it contains the energy of fire, that energy lies latent within. This is truly stabilized gold!”
Oruma’s praise did not cease.
“This is the essence of Metalum alone, something no other empire can even imitate.”
The retainers nodded one after another.
The Golden Core created by Metalum held meaning beyond that of a weapon.
It was Metalum’s pride, and a symbol of the dignity capable of absorbing and internalizing even fire, the most dangerous attribute.
“Now only one thing remains,” Oruma said quietly. “Deciding where this is to be used.”
From that moment on, the devices beneath the fortress began quietly transporting the Golden Core. The next barracks awaited it.
And before long, Oruma regained his composure.
Though it was gold, its value as a weapon was not particularly high.
For the fire energy contained within the Golden Core could instead threaten Metalum.
Oruma spoke to his retainers and researchers.
“We will not make immediate use of the Golden Core. Instead, as it carries great meaning in that we have reclaimed the name those ugly Ignis bastards stole without permission, have this Golden Core displayed in the plaza.”
Peron answered.
“Yes, I will follow your command.”
In accordance with Oruma’s order, the Golden Core appeared in the metal plaza.
And beside it, the Bronze Core was displayed separately.
Their distinctive colors seized the eyes of the citizens.
The yellow of gold and the blue of bronze.
The citizens conversed in front of the cores.
“My word, gold. Is this truly real?”
“The gold we wanted is here right now?”
“It’s not a core made by those Ignis bastards. It’s gold made with our technology!”
They continued their conversation as they looked at the Bronze Core as well.
“That one is a truly strange color too. I’ve never seen it before.”
“They say it came from fusing with wood.”
“So that was it.”
One citizen asked.
“But if bronze contains the energy of wood, does that mean it can attack Terra?”
“Hmm, I suppose so? As far as I know, the roots of trees are stronger than stone. Bronze should be even stronger.”
Another citizen agreed.
“That’s right. Bronze is a living substance. They say it’s more flexible than we are.”
The first citizen asked again.
“Then couldn’t we just take that Center for ourselves? Before, we marched our army to Terra as if we already had the Center, didn’t we? I heard the army came back our way because of Ignis, but now that those Ignis bastards have retreated, couldn’t we aim for the Center again?”
Another citizen shook his head.
“And get hit again? Above all, Terra has something called the Yellow Dragon or whatever it is. If we had a dragon too, maybe, but honestly, I think it’s a bit much right now.”
“Then are we at least preparing one?”
“I think we are. The order His Imperial Majesty gave was probably for that. If we’re going to reach the point of summoning a dragon, it would naturally require tremendous effort.”
As in the citizens’ conversations, Metalum focused on tempering itself rather than attacking other empires.
They did not produce troops with dual-attribute cores, and they temporarily put the training of their metal troop types on hold.
And those thorough preparations were finally nearing completion.
“Begin fortress modification.”
Oruma’s command fell.
As hundreds of Metal Cores accumulated until now were consumed, the fortress began its modification into its final stage.
Hundreds of steel assemblers who had trained for this day moved at once, diligently transporting reinforced metal plates.
They sealed the arriving metal plates onto the fortress’s outer walls, and in order to build higher, they erected and fixed several additional iron pillars.
Crasso, too, moved busily among the assemblers, assigning them roles and giving instructions.
He said,
“A fortress is originally a structure with high defensive power, but now this fortress will grow even stronger against external attacks. The more it is attacked, the harder it will become. This is who we are.”
It was not only the soldiers who defended against and fought external invasions.
The assemblers, too, were participating in battle.
Construction and modification work was physical labor, but at the same time, it was a kind of combat.
The assemblers carried out their roles with more vigor than ever.
“Begin reinforcement of the eastern outer wall! Attach double iron plates!”
“Install reinforced iron plates on the central dome ceiling!”
“Fortress foundation reinforcement complete! Twelve pillars installed! Installing pillar thirteen!”
Clank, clank, clank, whirrr, clang……
The noise of Metalum was like the sound of iron breathing.
Perhaps they were not merely “strong,” but “alive.”
Oruma looked down on all of this from the newly constructed outer control tower.
From there, Oruma’s voice spread outward.
“All citizens of iron, listen.”
His voice was low, but firm.
“This fortress is like a part of our bodies. The iron plates you have driven in are your exoskeletons, and the pillars you have raised are your structures. Now no one will dare bring down Metalum, or you. Steel remembers! And it answers with greater strength!”
Then the citizens all shouted the same slogans in unison.
“Steel remembers!”
“Steel answers with greater strength!”
Oruma returned to the fortress and looked beyond the window.
In the direction of his gaze lay the Terra Empire.
He remembered Terra’s words.
‘From the moment you spoke of the Center, the weight you must bear came with it. In other words, what you are saying is that you neglected your home base while guarding this Center—so how could you possibly be qualified to protect the Center?’
Oruma glared toward Terra and said,
“Wait, Terramont. I will soon bring my answer to your words.”
The vibrations spreading from Metalum reached the Terra Empire some time later.
Inside Terra’s underground fortress, Terramont quietly had his eyes closed.
“Is the balance of the world still far off?”
Now that all ten dual-attribute cores had appeared, with the Geyser Core as the last, Terramont was contemplating his next plan.
“When will the age of dual-attribute cores decline? When will the next age begin?”
The earth was still, but the moment when that silent attribute would awaken would come again without warning.