The waves began to surge with anger.
The southern Third Border of the Aqua Empire.
The surface, which had always flowed calmly, was now wavering somehow.
Following the Silva Empire’s lead, Aqua had concentrated on producing and deploying slime cores and slime infantry, only to allow Terra to launch a raid on their main base instead.
It had nearly become an occupation battle over who would seize the other’s citadel first, but the moment the defensive fortress built from slime cores collapsed before Terra’s earth guardians, Nereia, sensing the threat, had hurriedly decided to recall the slime infantry.
The slime forces returned in haste, but as soon as they arrived at the main base, the earth guardians also retreated.
In the meantime, a considerable portion of Aqua’s territory had been filled in with soil.
“Seven deep-sea regions lost……”
The officer in charge of restoration reported.
“The slime defensive fortress held out for quite some time, but the moment it collapsed, soil and rock surged in at tremendous speed.”
One of the tidal warriors also spoke.
“The southern central route is currently defenseless as well. We appear to be lacking forces for defense.”
Emperor Nereia was surveying the surroundings from atop the current near the border.
Behind her, her retainers followed in silence.
Levian quietly opened her mouth.
“It is as though…… while trying to use the current as a weapon, we missed the very pillar that supported that current.”
Nereia wordlessly looked down at the disordered coastline.
Along that coastline, the waves were also striking in irregular surges.
“It seems we forgot, for a moment, what makes us who we are. We, whose nature was condensation and flow, went too far in our advance.”
She placed her palm against the water’s surface.
The ripple that formed there slowly spread outward, reaching the edge of the territory.
“We must take this as a lesson. We have suffered greatly because of our excessive greed, but if we return to our original purpose, we can overcome this trial and return as an even stronger wave.”
As Nereia said, the defensive walls along the coastline began to be restored.
The waves were slowly returning over the areas that had been filled with soil as well.
The citizens of the Aqua Empire had also been deeply shaken by this invasion.
“I can’t believe it…… It’s a miracle we’re even alive.”
“This time was real. Terra’s bastards came at us last time too, but they only broke through the border and went straight back. But this time…… they almost reached the Blue Cradle.”
The citizens glanced toward Nereia’s citadel.
“If that place had been taken…… we would have been finished, wouldn’t we?”
“To be precise, we would have fallen under Terra’s rule. Terra would have monopolized all of our cores, too.”
Voices of dissatisfaction began to rise among them.
“So this is how it ended after all. Weren’t we so confident when we were expanding outward? And now we’ve retreated again?”
“They said we advanced all the way to Terra’s central region, so why did we retreat? We might have been able to take over Terra instead.”
“Were the slime soldiers not enough either?”
Some sighed, and others lowered their heads in disappointment.
Another citizen spoke up again.
“The best choice would have been not to attack rashly in the first place, but once they attacked us too, retreating was probably the better option we had. If we had continued a contest with the fate of the empire on the line, seeing who could seize the other’s citadel first, we might have lost. Honestly…… I never thought they would break through so terrifyingly far.”
Another citizen said,
“It was fine to increase the slime forces, but resource management seemed somewhat inefficient. With the cores needed to create one slime infantry unit, we could probably make three or four tidal warriors.”
“I don’t know. Still, isn’t slime the one thing that gives us a chance against Terra? Or maybe not.”
“In any case, the problem with this battle was that our side only paid attention to the front line and left this place far too vulnerable. Every wave core that appeared was made into a slime core together with Silva’s life cores……”
The currents drifting over the water’s surface occasionally shot off in irregular directions.
“They said slime infantry were that strong, but did we trust them too much?”
“They are strong, yes, but the problem must be that they’re expensive. Slime infantry are powerful, but they can’t be produced in large numbers.”
“Haa…… Meanwhile, it seems Terra’s forces are both strong and easy to mass-produce.”
One citizen joined their conversation.
“From what I know, Terra doesn’t even have dual-attribute cores. They leave their defense to Metallum, while they quietly gather their own cores. I hear the reason those two still haven’t cut ties is because Terra continues to pay Metallum something in exchange for protecting their land. Their own cores, perhaps?”
The citizens focused on his words.
“The trade is still continuing……?”
“We are maintaining relations with Silva too, but the method is somewhat different.”
The conversations flowed on, and that current slowly spread until it eventually reached even the inside of the citadel.
Nereia was quietly listening to their words.
She sank into thought.
She did not express dissatisfaction at the citizens’ voices, nor did she attempt to refute them.
But she felt it.
This invasion was not only a failure in battle, but also a crack in trust.
With a grave expression, Nereia slowly headed toward the throne.
She needed a certain conversation.
Of course, this battle had not brought only losses.
Aqua had once again had a considerable number of wave cores taken by Terra, but they had also acquired earth cores from Terra.
Chief Researcher Birellen and Senior Researcher Miriel had left the fusion facility located on the eastern border with Silva and were examining the earth cores in another temporary laboratory.
“This is…… Terra’s core?”
“It is certainly heavy compared to ours.”
A dark brown, solid outer shell. There was almost no fluctuation felt from within it, but its weight and density were distinct in and of themselves.
“This…… how are we supposed to handle it……?”
Miriel asked, flustered.
“Silva’s life cores accepted our flow well. But this does not accept us at all. On the contrary, it is damaging our wave cores.”
Birellen answered,
“Of course. Soil is, by nature, something that blocks our flow. Even so, we must find an answer.”
Miriel tilted her head.
“Why, exactly? Even if we fuse these to create dual-attribute cores, they will threaten us instead. Soil is already incompatible with us, and a core made from it would obviously……”
“No.”
Birellen spoke firmly.
“That is precisely why we must hurry. The more dangerous a core is to us, the sooner we must seize the initiative over it. If this falls into Terra’s hands, would that not make the situation even more serious?”
Miriel nodded, still wearing an uneasy expression.
She floated a wave core and an earth core over the condensed water surface and adjusted the wave interference between the two cores.
“I will try making it, but there will hardly be any occasion to use it, will there? We already have the definite weapon of slime cores, so why would we need to use this……”
“If there is a place to use it, it would be against Ignis, would it not?”
When Miriel looked at her, Birellen continued.
“The energy contained in slime is wood. Wood feeds fire, so it can interfere with extinguishing flames. But soil has little effect on fire. That means our water should be able to extinguish fire more reliably.”
Miriel thought to herself.
‘Would it not be better to train a new troop type with wave cores instead?’
In any case, the researchers began to devote themselves to fusing the new core.
The core itself might be dangerous, but if its affiliation could be set as Aqua itself, control would become possible.
That was why they had to fuse it.
Experiments on the new core began.
Nameless substance and nameless mass were waiting for a new name.
Meanwhile, in the central hall of the citadel, a map was floating above the water.
Around that map stood Nereia and her retainers.
They were reviewing the circumstances of the recent battle.
The advance of the slime forces. The successful collapse of Terra’s defensive line.
However, Terra’s counterattack. The retreat of the Aqua-Silva alliance.
Naus said,
“Even so, ordering the slime infantry to retreat was a reasonable choice under the circumstances. Terra’s forces also withdrew immediately after we retreated.”
At his words, Levian murmured to herself,
“Does that mean Terra never actually intended to occupy us……?”
Without showing any particular reaction, Nereia opened her mouth.
“We neglected balance. Even when advancing, securing our defense first should have been our priority.”
A quiet silence flowed for a moment before Sian spoke.
“The slime soldiers certainly performed well. There were simply too few of them. They remain worth using in the future.”
Levian muttered,
“If Silva continues to provide cores……”
Nereia opened her mouth.
“We allied with Silva and advanced toward Terra, and it was certainly effective. However, Terra is currently allied with Metallum as well. Why did they join hands with Terra?”
Naus answered,
“Metallum is said to be trading with Terra. The price is naturally Terra’s cores. Terra pays Metallum their cores, and Metallum protects Terra in return.”
Nereia turned her head and looked southwest.
“There is still an unresolved question. I must speak with Oruma directly.”
She began to move.
“I will visit Metallum for a short while. I will go alone.”
Oruca, the heart of Metallum.
The sound of footsteps along the cold metal walls was short and clear, like water flowing over stone and scattering.
When Nereia arrived before Metallum’s citadel, Oruma, the emperor of Metallum, appeared.
“Nereia of Aqua. To think you would send your current all the way here.”
Nereia stood in place.
Her voice was deeper than water.
“Terra invaded us. They committed a clear act of aggression, and we were forced back one-sidedly.”
Oruma gazed silently at Nereia.
Nereia continued.
“It was undoubtedly a calculated invasion. You were used by Terra. For the mere price of their cores, you have been drawn into their plan.”
Oruma was silent for a moment before answering.
“We merely followed our own order. The fact that you were invaded by Terra is none of our concern. And because we have received something, we are returning it. What have you given us?”
Nereia spoke as though sneering.
“So this is all Metallum amounts to in the end? To put it simply, does that not mean you willingly placed yourselves beneath them for the sake of cores?”
Oruma’s eyes began to tremble.
Even so, he soon regained his composure.
“If that is the only way you can see the relationship between us and Terra, then think as you wish. I have nothing to discuss with you. Answer my question instead. If you are dissatisfied with us being with Terra, why did you reject my request? Twice, at that.”
A brief silence.
The air was taut, as if metal and water were colliding.
Nereia said,
“We do not flow while calculating profit and loss as you do. We simply flow in the direction we wish to flow. I will be watching from now on as well.”
She turned away.
The walls of Metallum vibrated again with the spreading spray of water.
Oruma also watched her back for a moment before soon returning to the citadel.
The forest was quiet.
But its roots, like Aqua, were also shaken.
Silva had begun a joint attack with Aqua, only to suffer no small amount of damage from Metallum’s sudden attack.
It was time for Silva to need a different strategy for their own sake.