Chen Yu learned from Silver Sparrow that beneath this magnificent castle there actually existed an even more complex underground space, the true "heart" of the castle.
Inside were the core furnace chambers responsible for powering the entire castle, which consumed mana and spiritual energy to maintain the defensive formations, barriers, constant climate control, and various magical facilities covering the castle.
There was a main control room equivalent to the castle's "nerve center," filled with magic crystals and intricate control rune panels capable of directing the castle's overall operation, and there were propulsion chambers that could allow the castle to float and move...
Yes, the way this huge castle moved was by levitation.
Rather than calling it a castle, it was more accurate to call it a mobile aerial fortress, equipped with a complete set of formations and magical installations inside.
According to Silver Sparrow, when the castle's power was at full output, it could go toe-to-toe with epic-grade creatures, and thanks to its sturdy defenses and diverse offensive methods, it could even gain the upper hand.
Silver Sparrow stood before Chen Yu, hands properly crossed in front of her, her expression serious as she warned, "Master, the castle has been maintained at a low-power state for several hundred years. Most formations and facilities have been kept at the bare minimum, in ‘sleep’ for the majority of the time. For the castle's long-term health and functional integrity, please begin restoring its power supply as soon as possible."
"How do we restore it?"
If they could fire this thing up and set it loose, he didn't dare imagine how terrifying that would be. Casaric, the Demon Legion, the Burning Capital — he could just pilot the floating castle straight to Golden Radiance Valley and crush everything in his path.
Chen Yu's entire gel body shuddered.
An epic creature's body?
Rare materials?
And a Golden Core operator themselves.
He finally understood: the castle was essentially a treasure-grade artifact for a Golden Core; it was not something a Foundation Establishment little slime could casually control.
The good news was the Slime Kingdom had mined large quantities of Gray Gravel Crystal ore underground and had charged it using a Spirit Gathering Array, storing reserves in the kingdom's treasury.
Although Gray Gravel Crystal quality was far below those legendary rare materials, its advantage was abundance and its ability to store and convert spiritual energy.
In theory, as long as enough Gray Gravel Crystal was available, it might be possible to awaken the sleeping castle and restore its operation.
But with the kingdom's current Gray Gravel Crystal production, it was only enough to cover wartime routine consumption. Using it to power this gold-devouring behemoth of a castle might not even supply a fraction.
That made Chen Yu fixate on the main vein at Riftrock Pass.
He already knew the mining area beneath Riftrock Fortress was only the surface portion of a vast Gray Gravel Crystal vein.
The true main vein lay buried directly beneath the pass's mine, with astonishing reserves, but it had long been controlled by goblins and only used to produce magical dust, a lower-value magical material.
Now that the Goblin Army had fled, Riftrock Pass effectively fell under Slime Kingdom control. Developing the mining area could still offer hope of accumulating enough Gray Gravel Crystal to start up the floating castle.
Seeing the castle's array of miraculous functions also sparked many ideas in Silver Sparrow's mind.
Traditional battlefield-line tactics with a magical creature legion were ever harder to deal with against these low-walled fortifications built on key terrain.
If the enemy had no Extraordinary present, almost every battle dragged away part of the kingdom's manpower and resources, and casualties were often large.
Growing Arcane Ancient Trees to Gold-Rank took a long time; the kingdom currently lacked effective weapons against demons and neighboring states' wars.
Silver Sparrow's first thought was artifact refinement: forging Extraordinary-grade weapons to deal with the Extraordinary. Swords, spears, halberds and the like were straightforward, but their impact radius was limited.
What I can do is imitate that castle’s design philosophy and some of its principles, and create a large-scale "mobile war fortress," a weapon capable of directly deciding a battle's outcome.
Faced with a war fortress that could hover in the air and mount powerful firepower, traditional terrain-dependent defenses and high walls would become meaningless.
This would not only be a weapons upgrade but a fundamental change in how wars were fought, far more disruptive than the slow, painstaking cultivation of a handful of Extraordinary units.
Silver Sparrow automatically applauded, saying, "This idea is brilliant, Master. You're amazing."
"Is it achievable?" Chen Yu blinked, ignoring her lack of emotion in flattery, and asked seriously.
Silver Sparrow bowed, "I can draw a complete blueprint of the castle for you and provide basic formation principles and structural research guidance, but to actually develop the 'war fortress' you envision will require deep involvement from more of the kingdom's specialized craftsmen."
That was indeed the problem.
A simplified war fortress might look like a scaled-down, simplified version, but in reality it involved cooperation across the kingdom: craft scheduling and skill, formation research and engraving, fortress structural design and material selection, miniaturization and efficiency of power systems, integration and control of weaponry... countless aspects. It was an extremely complex project, not something easily solved.
In short, first send a batch of Slime Scholars and dwarf artisans to study under Silver Sparrow, lay the foundation, and then proceed.
After gaining control of the castle, Chen Yu let the main force of the Magical Creature Legion waiting outside enter.
The legion rested in the manor grounds outside the castle. Arthur paused as he passed through the garden where hundreds of flowers bloomed.
The pale blue soulfire under his helmet flickered violently as if it had seen a precious treasure. He even crouched down, iron-armored fingers reaching out to gently touch a dewdrop-laden golden sunflower, moving so softly as if afraid to disturb it.
His posture was exactly like an old farmer discovering a previously unseen fertile new land, full of curiosity and joy.
"Beautiful..." Arthur murmured under his breath, his voice hoarse yet laced with an indescribable emotion.
Count Bran grew even more excited, squealing and flapping his wings as he darted around above the castle.
One moment he flew to the top of a high tower to survey the view, the next he dove into an archway draped in wisteria to explore, then tried to peck the automated furniture with his beak, only to be chased around the great hall by a broom; several feathers fell but he remained delighted.
Olivia floated behind Chen Yu, who was riding a sword, and her gaze landed on Arthur, who was still crouched among the flowers. Her silver eyes lifted slightly.
"The way of nature?" she whispered to herself, then looked at Chen Yu with a smile curling at the corner of her mouth. "It seems the outside is much more interesting than I imagined."
"Your Majesty." Arthur sensed the gaze, rose, and performed a standard Knight's Salute toward Olivia and Chen Yu.
That made Olivia even more intrigued by this peculiar Death Knight.
"You've never been out?" Chen Yu looked at Olivia with some surprise.
He had assumed the silver dragon had already quietly ventured out to observe the swamp and surrounding conditions. It now appeared she had rarely left the castle.
Olivia shrugged, "I'm sorry to disappoint our Majesty, but for certain special reasons I cannot leave this castle for long distances."
"The farthest I went was to visit a dryad sage hiding deep in the swamp, and I glimpsed the goblins' fortifications at the pass, but I have not formally visited your Slime Kingdom."
She had met Viola?
How many things had this creature not told him.
Chen Yu considered it and found that was actually fine.
With Olivia the silver dragon watching over the planar rift on the snowplain, there would at least be nothing strange coming from that rift to cause trouble — a free, powerful mercenary and gatekeeper.
He would be happy for Olivia to stay for decades, so he tacitly avoided any discussion about her departure.
Afterward, aside from some gargoyles stationed on the snowplain to help guard the rift and establish an outpost, the Magical Creature Legion’s main force split into two. One group, led by Chen Yu, would head to Riftrock Pass to fully recapture the mines.
The other, led by Arthur and Count Bran, would return directly toward Storm Fortress to prevent the rear from being hollowed out and giving the returning Demon Legion an opportunity to strike.
Olivia seemed familiar with Riftrock Pass. Before Chen Yu left she called to him and handed over a small crystal ewer filled with about half a bottle of a faintly silver-glowing liquid.
Olivia looked at Chen Yu with her silver eyes and said meaningfully, "The situation there is more interesting than you think. If you encounter 'stubborn stone' that cannot be dissolved, pour this on it and you'll get what you want."
Although Chen Yu was puzzled, he accepted the potion, stored it inside his gel belly, bid Olivia and the castle a temporary farewell, and set off on the return.
Half an hour later, Riftrock Pass.
The Magical Creature Legion easily took control of the now-empty Goblin Fortress. Chen Yu stood on a ruined crenel and looked down into the bottomless mine shaft.
Now he finally understood what Olivia meant by "stubborn stone."
Near the mine entrance lay a colossal body.
It was not ordinary rock but a fully petrified dragon corpse, and judging by the skull contours, thick bone structure, and the faint, lingering draconic majesty even through the stone, this was no subdrake but a black dragon with pure bloodline.
The dragon's body nearly blocked half the mine entrance. It held the posture of a final, struggling moment, its head thrust upward, jaws wide open, as if emitting a silent roar.
So the last mana turbulence at the pass had been severe enough to attract a dragon and turn it completely to stone.
He now realized the obstruction in the mine entrance was not ordinary stone at all. The material Iron Anvil used to forge the Goblin Ripper cannon frame was not some special metal but scales fallen from this petrified black dragon.
A dead dragon's scales, fangs, and bones all carried immense value as top-tier magical materials and forging raw materials.
Especially the dragon's heart: it was said that a warrior who bathed in a dragon's heartblood could undergo a rebirth-like transformation.
But this dragon had been entirely petrified; its heart had likely turned to stone long ago, losing all vitality and energy.
However...
Chen Yu looked at the faintly silver potion floating in his gel belly and understood Olivia's intent.
...
White Horse Kingdom, eastern city Ferando.
In a dim room in the noble quarter with curtains drawn tightly.
On the floor fresh blood had not yet fully congealed. The sacrificial array lines carved into the floor seemed to writhe and squirm, filling the air with a nauseating metallic stench.
Surrounding the room stood several knights and ministers in luxurious attire, watching intently the two figures standing in the middle of the sacrificial array. The atmosphere was suffocatingly tense.
In the center of the array stood a young man of about twenty.
He wore a tailored princely suit made of top-quality velvet from the southern Jade River valley, with a white horse crest at his collar marking royal status.
I had neatly combed chestnut hair, a delicate face, but at this moment I was completely pale without color, lips pressed tight, a fine sweat beading on my forehead.
My name is Alec von Whiteman, the eighth in line to inherit in the White Horse Kingdom.
Standing beside me was a short, compact figure exuding a terrifying aura — the Iron Cavalry demon who had escaped from Storm Fortress, Ea in his armored form.
Alec took a deep breath, trying to calm the heart threatening to leap out of his chest; he could vaguely hear his own blood rushing and felt the hand on his sword hilt trembling.
He turned to the silent slime beside him and bowed as steadily as he could, "Lord Yex, please... begin the sacrificial ritual."
As the kingdom's third-ranked heir, Yex deeply understood that the mediocre Alec could never vie for the supreme throne squeezed between the brilliant and favored eldest prince Karl and the second prince William, who had military achievements and the northern nobility's backing.
He was like an unremarkable backdrop at court banquets — unnoticed and unanticipated.
He still clearly remembered when he was ten, winter winds stinging his face until it ached, nose tip reddened. Dressed in solemn attire at the capital's illustrious square, he stood with his two elder brothers and solemnly swore to his father, Rittreil von Whiteman: "In the name of the sun Ignis, I will be loyal to the kingdom all my life, protect the people, and defend the honor of the Whiteman family!"
But his father's blue gaze had lingered on him only a moment before moving on to the more remarkable elder sons.
That indifference, though he had long since grown used to it, remained etched in his memory.