Of course, within the Fierce Ghost Army and the Latent Dragon Army, there were also numerous Golden Core realm cultivators. However, these Golden Core experts, having been tempered by warfare and through their own diligent cultivation, were now, at the very least, at the High-tier Golden Core stage. Especially within the Fierce Ghost Army, High-tier Golden Core Ghost Generals were extremely numerous, comprising the vast majority, being either High-tier or Peak Golden Core.

As for this contingent, Lei Dong currently possessed sufficient resources to facilitate their breakthroughs.

Now, Lei Dong took stock of his current strength. Taking the Latent Dragon Army first, after continuous fierce fighting, only 4,500 soldiers of the Latent Dragon Army remained alive. The survival rate was so high due to Lei Dong's rotating shift tactic: whoever was injured would immediately enter the Grotto-Heavens and Blessed Lands to recuperate and cultivate, returning to replace their comrades fighting outside only once healed.

Consequently, generally, as long as they weren't killed instantly, the vast majority could be saved. Among them were quite a few instances where individuals achieved spontaneous breakthroughs after experiencing life and death.

Without abundant resources, Lei Dong had no choice but to select them to advance naturally within the Grotto-Heavens and Blessed Lands.

Fortunately, there was still a year remaining, during which the Grotto-Heavens and Blessed Lands functioned as ten years; some lucky individuals might even manage to sprint from Peak Golden Core all the way to Nascent Soul.

However, Lei Dong suddenly considered: since the surrounding world was saturated with pure Chaos Spiritual Qi, why not try to see if the world's essence could be swapped with that inside the Grotto-Heavens and Blessed Lands? After some experimentation with array formations, Lei Dong easily mastered this method.

By maintaining the connection channel open for extended periods, Lei Dong utilized two simple arrays to continuously draw the air from the Chaos Heterogeneous Space into the Grotto-Heavens and Blessed Lands. Since the Grotto-Heavens and Blessed Lands had only grown to a mere few dozen miles in circumference by this time, it wouldn't take long to equalize the air within to match the outside world.

Naturally, this wasn't without side effects. The primary issue was that the prolonged opening of the connection channel caused the Heavenly Spirit Stones embedded within the Grotto-Heavens and Blessed Lands to be consumed at double the rate. The Time Law Array, which could have sustained the Grotto-Heavens and Blessed Lands for about ninety years previously, now seemed capable of lasting only half that time after this undertaking.

Furthermore, Lei Dong had previously discovered that if too many or too powerful beings gathered inside the Grotto-Heavens and Blessed Lands, the energy consumption of the Time Array would increase accordingly. The reason was simple: for the same array, making more people experience a different rate of time naturally demanded more energy expenditure.

Likewise, the energy required for the same array to affect a Soul Transformation stage expert or a Nascent Soul expert differed. This was why Lei Dong had previously been reluctant to place anyone who had achieved the Soul Transformation stage inside the Grotto-Heavens and Blessed Lands for cultivation.

But now, at this critical juncture, Lei Dong could no longer afford hesitation. Following discussions with the Netherworld Ghost Emperor and a group of other behemoths, those needing advancement were placed inside the Grotto-Heavens and Blessed Lands to cultivate. He then recklessly threw all beings who had not yet reached the Nascent Soul stage into the Grotto-Heavens and Blessed Lands en masse.

The rate of energy consumption immediately skyrocketed by several times. Lei Dong calculated the consumption rate more precisely: this batch of Heavenly Spirit Stones could sustain operations for only about ten more years. This equated to Lei Dong making a desperate gamble, staking everything to boost his power.

This frantic effort was not without reward for Lei Dong. Especially for those Ghost Generals or Latent Dragon Soldiers at the Golden Core stage who hadn't yet ascended to Nascent Soul, Lei Dong could not provide them with sufficient Chaos Crystals. But continuously infusing vast amounts of Chaos Spiritual Qi air allowed them to absorb it from the atmosphere and advance naturally, and the effect seemed quite good.

They were at least Upper-grade or Top-grade Spirit Ghosts in terms of aptitude. Cultivating in isolation for ten years might yield average progress. But cultivating in seclusion for ten years within a place saturated with Chaos Spiritual Qi made a world of difference.

As for opening the Grotto-Heavens and Blessed Lands to the Netherworld Ghost Emperor and the others, after their initial astonishment, they were all ecstatic. With Lei Dong possessing such a heaven-defying treasure, what was there to fear? No wonder the boy had been frantically collecting Heavenly Spirit Stones outside—it was because he held this extremely effective treasure that voraciously consumed them.

However, they had no frivolous thoughts now; the top priority was seizing every moment to cultivate. Whether it was the Netherworld Ghost Emperor or the Purgatory Demon Lord, both were confident that with one Chaos Crystal plus ten years of secluded cultivation, they could directly break through to the High-tier Soul Transformation stage. Overcoming this bottleneck that had stalled them for so long was undoubtedly exhilarating. It had been a long time since anyone in the Six Domains and Nine Continents had managed to break through to High-tier Soul Transformation. The two behemoths began to fiercely compete to be the first to achieve this rank.

Lei Dong and those not yet requiring advancement naturally would not waste resources. Thus, taking the Soul Transformation experts as the unit, he led a group of equally unconcerned Nascent Soul masters to venture into the depths of the Chaos Heterogeneous World for reconnaissance, to collect the Chaos Spiritual Qi from the arrays they had deployed, and also to attempt mining natural Chaos Crystals in the wild. So-called natural Chaos Crystals were formed in a place rich in Chaos Spiritual Qi, where certain minerals capable of absorbing Chaos Spiritual Qi would slowly accumulate the essence year after year, gradually transforming into pure crystalline bodies.

It was rumored that in ancient times, or the Savage Era, mining Chaos Crystals or cultivating with Chaos Spirit Herbs was the mainstream method. Only after Chaos Crystal resources became scarce did people begin to consider whether it was possible to gather the scattered Chaos Spiritual Qi floating in the world and refine it into artificial Chaos Crystals.

Therefore, based on intelligence projections, this Chaos Heterogeneous World might contain some natural Chaos Crystals. Perhaps they had already been mined, or perhaps they were inherently rare. But generally, as long as comprehensive, earth-shattering mining hadn't occurred, some residue would always remain.

Moreover, given the situation where the Chaos Spiritual Qi here hadn't been harvested through brutal means, even if this Chaos Heterogeneous World had undergone Chaos Crystal mining, it couldn't have been an extermination-level extraction.

Because, for those ancient cultivators, while Chaos Crystals were excellent, they weren't worth scouring every corner, not even letting slag remain, as they would in the case of total desperation. It was similar to how Lei Dong might not bother collecting mineral materials usable only by Qi Refining or Foundation Establishment cultivators. After all, almost anything else earned more profit. Even killing a Nascent Soul expert and seizing their treasures would yield profits many times greater.

Thus, Lei Dong sent out several teams, partly hoping to try their luck and see if they could scavenge anything. Even discovering a microscopic Chaos Spirit Vein would send them into raptures of joy. Furthermore, Lei Dong was largely unconcerned about that damned Night Emperor.

Although the Night Emperor's faction was powerful, it also had a massive inherent flaw: his subordinates were all beings possessed by Heart Devils, who had taken control of their physical bodies. Lei Dong had similar entities among his forces; the White Armor Soldiers, fewer than five hundred remaining, were prime examples.

Such experts controlled by Heart Devils could certainly be fierce and terrifying on the main battlefield or when directed. But if one expected them to form small teams to carry out complex missions—patrols, assassinations, collection, etc.—it was pure folly. Abyss Lord Birdis had deeply experienced this; he was nearly driven to collapse by the infiltration tactics of the Holy Radiance King's small teams.

Their utility was equivalent to that of a weapon; how could one assign a weapon a mission? The Heart Devil army, lacking intelligence and possessing only fanatic combat instinct, was indeed fearsome, but one simply shouldn't charge their main camp. And the enemy's sole intelligent entity, the Night Emperor, why would he bother hunting down Lei Dong's secretly operating small teams?

Due to these various factors, Lei Dong here was not completely hemmed in by the Night Emperor. By actively moving about, even if the Night Emperor dispatched patrol teams, it would be futile. Those Heart Devil 'brothers' possessed extremely low autonomy, being stiff and essentially low-intelligence puppets. If there was no direct conflict, they could easily be bypassed.

Gui Ming, Gui Ci, Tian Mo, Dongfang Fu, Xuan She, Xiao You, Xie Feng, Yaksha King, You Ming Mo, and others—these close associates or direct subordinates temporarily exempt from advancement—each led a small team of about a dozen stealth-capable Ghost Star level Fierce Ghost Soldiers, scattering in all directions to conduct searches.

As for Wan Yan, Lei Dong stationed her at the main camp as a precaution. However, Lei Dong was certain that the Holy Radiance King's group would not dare to launch a direct attack, nor would they dare a stealth raid on the camp. Even if they did, Lei Dong wouldn't care; the Grotto-Heavens and Blessed Lands remained in the main camp—whoever dared stir trouble would be courting death.

Lei Dong himself led the tenth search team. His entourage comprised the most elite of the Latent Dragon Soldiers, along with a young man who bore a slight resemblance to Lei Dong but appeared unfamiliar, forming a fifteen-person squad.

That young man’s gaze was sharp, his aura powerful, faintly revealing a chilling, soul-stirring coldness. Yet, towards Lei Dong, he displayed an overwhelming sense of kinship.

"Lei Hu, you've only just achieved human form recently. Familiarize yourself with your current strength and body," Lei Dong commanded silently, spreading his divine sense across all directions, even seeping into the deep fissures of ravines, attempting to locate anything unusual.

"Yes, Master," the Lei Hu responded respectfully in halting, half-familiar speech.

"Lei Ying, I've told you many times, just like Lei Long, call me Big Brother," Lei Dong said affectionately, patting his shoulder with warmth. "Since the day we parted ways, we grew up almost inseparable. We shared every secret, every hardship, every tribulation. I never treated you as a mere spirit pet; you were always my brother, Lei Dong. Now that you have a human form, you should rightfully become my third brother, Lei Dong."