The Forbidden Breakthrough

The instant Jin Somyeong fed twenty high-grade Spirit Stones into the Mental Secret Realm, the spirit vein—until then a second-rank commodity—began to grow at a furious pace.

At the very moment the twentieth and final high-grade Spirit Stone vanished, the air changed.

The spirit vein had taken one step beyond the second rank and reached the third.

Jin Somyeong measured the energy flowing in from somewhere deep within his body, from a place connected to his soul, and felt relief settle over him.

I can handle this.

The energy thickening inside the Mental Secret Realm after its ascent to the third rank had increased by roughly tenfold. His meridians throbbed faintly, but he trusted they would soon adapt. Of course, if this sort of energy had erupted inside an ordinary Foundation Establishment cultivator, their meridians would have burst and killed them on the spot. Jin Somyeong, however, possessed a body refined to the third rank; he could contain it without trouble.

My cultivation will speed up even more.

As a test, he circulated the Cheonroedochegyeol. Judging by how quickly spiritual power gathered in his dantian, it seemed he could reach the ninth layer of Foundation Establishment in roughly five or six years.

And if I borrow a third-rank cave abode on top of this, it’ll be faster still.

There was no need to worry about the rent. Because he belonged to the Red Flower Unit and had taken part in the war with considerable enthusiasm, he was swimming in contribution points.

A smile rose unbidden as the hologram appeared before his eyes. High-grade Spirit Stones, considered precious even on Sky Island, would now appear one per day.

Once his satisfaction had settled, he turned his gaze elsewhere and took in the Mental Secret Realm, which had grown noticeably wider than it had been only a few minutes before.

Forty or fifty thousand pyeong? That’s enormous.

The Mental Secret Realm, which had first been no more than a small hill, had expanded until it was large enough to build a castle on.

At this size... I could even make a training ground.

There had been one inconvenience he had felt ever since awakening Condensing Light to Extinguish Dust. Golden Core-grade spells were all too powerful. Finding a place where he could practice them comfortably was difficult. But now that the Mental Secret Realm had grown this much, he thought he might as well construct a training ground.

He swept his Sword Qi out in a broad arc, shaving one side of the hill flat before pressing it down with vast spiritual power. After tapping the densely compressed earth a few times, he nodded. It was ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠harder than most steel, which made it satisfactory enough.

Hmm.

He looked over the training ground he had ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠made himself. It was flat and spacious, perfect for practicing spells, but because there was nothing in it, it felt strangely barren. After thinking for a moment, he took out several logs, carved them into scarecrow shapes, and set them up in one corner.

...Good enough. I’ll improve it later.

For a moment, he pictured something like the simulation training rooms he had seen in movies. If he could fight enemies safely in a virtual space, it would be a great help in mastering various spells...

He laughed softly at the idle thought.

Since I’m here, I might as well stop by the Blue Light Spring.

He headed toward the lightning-attribute spirit spring, where rolling thunder and blue light poured forth. Because he had been too busy to visit for the past several months, lightning energy had accumulated in abundance.

Without hesitation, he lowered himself into the open-air bath, where threadlike blue lightning crawled across the surface of the water.

Crackle!

He circulated the Cheonroedochegyeol, now at the mastery stage, and absorbed every bolt that came crashing down. He converted the lightning energy into spiritual power and stored it layer by layer within his dantian.

Hoo...

The flashing Blue Light Spring turned as plain as ordinary water in an instant. A smile came to him naturally. In barely an hour, he had gained the amount of spiritual power that would have taken several months of cultivation to accumulate.

I should go back out and keep cultivating.

Having finished his business, Jin Somyeong was about to return to his cave abode when he suddenly stopped. He had sensed a change from the center of the Mental Secret Realm, at the very peak of the hill—the place where he had planted the sword seed.

"Oh?"

He could have discerned the change through Divine Sense, but he wanted to see it with his own eyes. He hurried to the place where the sword seed had been planted.

"It finally sprouted!"

A small shoot peeked out from between the clumps of soil. It seemed to have germinated after he replaced the second-rank earth with the third-rank spiritual soil obtained from Hyeok Cheon-ung, and after the growth of the Mental Secret Realm influenced it.

Jin Somyeong stared blankly at the silver leaves wrapped in Sword Qi, veiled in a faint shimmer like heat haze. After nearly nine years of devoted care, the seed had finally sprouted, and his chest swelled with emotion.

Perhaps sensing his arrival, the silver shoot swayed gently, as though greeting him.

It’s kind of cute.

The moment he carefully stroked it with the tip of his finger, a sharp, prickling edge brushed against his skin.

"Hm?"

It did not hurt, but it puzzled him. As he stared at it, he heard something like a faint whisper, like the fretful whining of a newborn. More precisely, it was closer to a vague will or emotion than actual sound.

"...You’re hungry?"

Apparently it had not been greeting him after all. It had simply been asking for food.

He flicked his finger. When he condensed Sword Qi and sent it toward the sprout, it devoured the offering as if it had been waiting. It was a complete glutton.

Watching it absorb as much keen energy as he gave it, endlessly and without restraint, he suddenly thought of a name that suited it perfectly.

"From now on, your name is Mugeuk."

The silver shoot fluttered like a sparrow’s wings. Whether that meant it liked the name or disliked it, he could not tell. The thing was simply too busy eating Sword Qi.

"...Once you grow stronger, I’ll add ‘Divine Sword’ to the end."

After pouring in another two thousand units of Boundless Great Ability as a final gift, Jin Somyeong left the Mental Secret Realm.

Lately, things had felt auspicious. At times like this, he needed to focus on cultivation and raise his realm.

Before he knew it, five years had passed.

Jin Somyeong reached the ninth layer of Foundation Establishment.

The Mental Secret Realm, the miniature Blue Light Spring, the straw meditation mat that increased the speed at which he accumulated spiritual power, the medicinal pills he swallowed as casually as water—surrounded by a blessed environment like that, he had cultivated without taking even a single day off. This was the fortunate result.

After reaching the ninth layer, Jin Somyeong rested for exactly one day.

With Golden Core, the realm after Foundation Establishment, right before his eyes, he did not want to rest. Instead, he accelerated his cultivation even further. The moment he judged that his meridians had adapted to the high-density spiritual power, he moved cave abodes. Using both a third-rank low-grade cave abode and the Mental Secret Realm, he continued cultivating.

Another five years passed in that way...

Ordinarily, anyone who reached Golden Core before the age of one hundred was regarded as a heaven-sent genius. Jin Somyeong, however, had already gone far beyond that standard.

At the absurdly young age of his early forties, he had climbed to the very limit of what could be achieved within Foundation Establishment—even leaving aside the fact that his body refinement had already reached the third rank.

Hoo.

Having reached the end of Foundation Establishment, Jin Somyeong rested for a full month. He relaxed the body and mind worn down by ten years of cultivation, wandering the marketplace with no particular purpose and truly doing nothing at all as he shed the fatigue that had accumulated within him.

The moment he recovered to perfect condition, he returned to his cave abode and sat cross-legged.

...Good.

Everything was ready now.

Only one thing remained: to ingest the Hundred Spirit Grass, the Golden Core spiritual item, and form his Golden Core.

On an uninhabited island near Sky Island—

A tiny islet with no distinguishing features beyond the colorful shells scattered across it—sixteen demon beast kings gathered in secret.

One of them, who had been observing Sky Island from afar, turned his gaze aside and glared at the golden-furred ape with open irritation.

"Golden-furred Sacred Ape. You clearly said that if fifteen demon beast kings gathered and attacked at the same time, we would be able to break Sky Island’s formation. Do you remember that?"

"Yes. That is what I said."

"Then what is this? Even I, who know nothing of such matters, can see that Sky Island’s formation has changed completely from before."

At that accusing tone, the other demon beast kings chimed in.

"He’s right. Anyone can tell those damned humans’ formation has become several times stronger."

"It looks like they’re using the spirit vein... Are you truly certain we can break the formation if we attack?"

Under the gazes stabbing in from all directions, the Golden-furred Sacred Ape chattered with laughter and readily admitted it.

"Correct. The humans have combined the spirit vein with their formation. A truly impressive feat. At present, even if we attacked for an entire month, the Reverse Extreme Locking Formation would remain perfectly intact."

"You wretched bastard! Why are you admiring it? Then doesn’t that mean we handed over a third-rank peak-grade spirit vein for nothing because of your nonsense?"

"You took high-grade Spirit Stones from us claiming you’d study the formation! What in the world have you been doing all this time?"

The demon beast kings who had been snarling in irritation suddenly paused. The Golden-furred Sacred Ape was smiling so brightly that every one of his teeth showed.

"Keh-heh-heh. Don’t be so hasty. If the spirit vein is the problem, we simply have to destroy the spirit vein, don’t we?"

"...Is that even something that can be destroyed?"

Even the demon beast king who had been raging fell silent, looking stunned.

Perhaps things were different elsewhere, but in this sea, spirit veins had no physical form. They were merely places where spiritual energy welled up for reasons unknown, and so they were called spirit veins.

"It is possible with a formation. One blocks the flow of spiritual energy and detonates it."

"No, wait. Then what happens to the third-rank peak-grade spirit vein?"

"It will, naturally, be ruined. It will split into hundreds or thousands of fragments and scatter throughout the sea."

"...Would that not be a tremendous loss to us as well?"

If it merely split apart, that would be fortunate; in all likelihood, its grade would also fall. In other words, the places where the demon beast kings cultivated would vanish.

The corners of the Golden-furred Sacred Ape’s cheerful smile twisted. He spoke in a delighted tone, as though the situation amused him beyond measure.

"If we can wipe out those detestable humans in one stroke, what does a trivial loss like that matter?"

"...Now that I see it, you are the most extreme one here."

The demon beast kings exchanged looks. Most of them were plainly reluctant.

The spirit veins currently occupied by the humans amounted to roughly one-third of the whole. More than half still lay within the territory of the demon beasts. Destroying the spirit vein was a foolish act of cutting away one’s own flesh.

Perhaps because of their lukewarm reaction, the heat vanished from the Golden-furred Sacred Ape’s voice, and it sank coldly.

"Tsk. If petty profit matters to you so much, then allow me to explain it another way. What happens if we topple Sky Island this time?"

"Hm...?"

"We demons live far longer than humans. Imagine one hundred years from now. By then, without even needing to compete with humans, this entire sea will belong to us."

One hundred years. ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠It was an exceedingly long span of time.

Even if they ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠shattered Sky Island this time, humanity likely would not collapse immediately. The war would certainly grow far fiercer than it was now. No one knew how many of the demon beast kings gathered here would die in the effort to exterminate every human.

Unless they intended to sacrifice themselves for the next generation, it was not a choice anyone would welcome.

"..."

The mood split in two. The lone demon beast kings naturally disliked the proposal, while those who served as leaders of their respective races looked tempted.

Just as a strange silence settled over them, a disturbance arose in the skies above Sky Island.

Thick black clouds formed overhead, and the spiritual energy of heaven and earth within a radius of dozens of li gathered in a whirling storm.

"That is..."

"Golden Core! One of the humans is about to become a Golden Core cultivator!"

Their gazes snapped around even as they cried out in shock.

Behind them, the sea split open, and a fish-dragon with golden scales emerged. Clouds coiled around its claws like those of a legendary dragon, lending it a majestic bearing.

The appearance of a late-stage Golden Core fish-dragon threw the demon beast kings into confusion.

The sea dragon race was arrogant by nature and treated other demon races like beasts. Though not as hostile as they were toward humans, their relationship was still anything but pleasant.

"No... Why are you here?"

"I invited him. We need an expert capable of facing the late-stage Golden Core master of Sky Island, do we not?"

As the Golden-furred Sacred Ape spoke with laughter in his voice, the fish-dragon overwhelmed everyone with its immense magical power and issued an order.

"This is perfect timing. If you damage the spirit vein now, that human will fail to ascend to Golden Core. Begin at once."

Meanwhile, Jin Somyeong, who had been challenging Golden Core with all his strength, furrowed his brow.

The spirit vein had suddenly become unstable. The spiritual power that had been flowing in at a steady rate now came in broken, stuttering bursts.

"...Tsk."

He did not know the reason, but the solution was simple.

He entered the Mental Secret Realm and poured in the high-grade Spirit Stones he had gathered over the past ten years.

He strengthened the Mental Secret Realm, which he had previously kept at precisely the right level so that it would not place undue strain on his meridians.