Beyond these core lineage members, there was a contingent Lei Dong paid significant attention to: the Hidden Dragon Army, which he highly valued. Although currently comprising only seventeen children just beginning their cultivation, Lei Dong knew that given time, and as the numbers swelled, this force would inevitably grow into one renowned across the lands.

Mind control via Gui Gu was essential, and indoctrination from childhood was a must.

Qing Niangzi and other close confidantes of Lei Dong were temporarily positioned outside, continuing their mission to expand and consolidate his influence, while also bearing specific mandates. For instance, they were tasked with gathering intelligence on exceptionally gifted, late-stage Golden Core experts among the rogue cultivators, particularly those with specialized knowledge, such as Gu Mo. Unsurprisingly, Lei Dong harbored intense covetousness for these individuals; even subjugating a few would greatly bolster his strength.

Furthermore, the Earth Giant clan represented another significant hope for Lei Dong. Vast quantities of elixirs were channeled to the chieftain, Yan Shi, through various means, along with a message urging him toward an early breakthrough to the Nascent Soul stage. The Earth Giant clan valued strength above all else. Should Yan Shi achieve Nascent Soul power, he could immediately begin annexing smaller tribes and massively expanding their might. A single Golden Core Earth Giant might not be formidable, but a massed army of them was terrifyingly potent; bolstered by their formidable innate abilities, assembled Earth Giants were veritable Nascent Soul slayers.

Lei Dong could not afford to neglect the Nether Domain either. He dispatched Shangguan Hong directly to establish contact with the old demon Hu Yan, whom he had previously subdued, intending to gradually expand his presence there.

After setting these arrangements in motion, Lei Dong commenced his period of secluded cultivation.

Time slipped by swiftly. Four years passed in a flash. During this period, Tian Mo returned, dust-caked from his journey, bearing elixirs of staggering value. If all these pills were liquidated, Lei Dong’s spiritual stone funds could potentially reach ten billion.

However, Lei Dong hesitated to sell everything in Kang Province, as the massive injection of capital had already driven up the prices of local specialties considerably. While selling would yield profit, purchasing more elixirs in Zhao Province would hardly be cheap.

Yet, some less critical elixirs could certainly be offloaded into the Nether Domain. That realm was vast, and its demand for pills was equally immense. Dumping those supplies there would likely barely cause a ripple. Cashing in would also allow him to acquire a cache of Yin Sha Heavenly Thunder from the Nether Domain.

That substance was incredibly cheap there yet possessed devastating power. In the previous encounter, Lei Dong had relied heavily on a large quantity of Yin Sha Heavenly Thunder to severely wound the Heavenly Ghost Emperor, ultimately securing victory. This potent heavenly thunder, capable of harming even Deity Transformation experts, could undoubtedly obliterate a few Nascent Soul cultivators if deployed recklessly. Its only drawback was that it was consumable, costing tens of thousands of spirit stones each—every deployment was a drain on his wealth.

Of course, injuring the Heavenly Ghost Emperor previously was partly due to the Nether Ghost Emperor’s assistance, freezing time for a few critical breaths with the Nether God True Word technique. Otherwise, with Lei Dong’s own capabilities, even simultaneously hurling a hundred Yin Sha Heavenly Thunders would fail to strike the Heavenly Ghost Emperor. Thus, while this item sufficed against Nascent Soul cultivators, it might prove inadequate against Deity Transformation masters. With his current understanding, Lei Dong was not qualified to grasp such a profound technique as the Nether God True Word, which could alter the laws within a localized area.

Over four years, the surface remained calm. The Yaksha clan, which had agreed to monitor the movements of the Grand Supreme Sect, reported no sightings of their forces appearing at sea.

But Lei Dong was forced to emerge from seclusion regardless.

In truth, had unexpected complications not arisen, and if the Grand Supreme Sect had not been delayed, Lei Dong would have gladly continued his closed-door cultivation within the Grotto-Heaven Paradise indefinitely. But life, as they say, rarely conforms to expectations.

At the four-year and three-month mark, the Grotto-Heaven Paradise abruptly underwent a shift. The spiritual energy thinned to almost nothing, and the temporal flow between the two internal zones suddenly synchronized. In essence, the Paradise’s unique effects vanished entirely.

With a grim expression, Lei Dong meticulously examined the Paradise’s mechanisms and discovered that it had always been powered by an ancient, complex, and powerful grand formation.

That formation was so potent it could not only generate pure, abundant spiritual energy but also twist the laws of time, creating a discrepancy between the time flow inside and outside its boundaries—this was the source of the Grotto-Heaven Paradise’s previous effects.

However, the earlier Lei Dong had overlooked one crucial point: the Law of Conservation of Energy. Lei Dong couldn't ascertain the exact cosmological level of this law, but he was now certain that even this miraculous ancient formation could not violate it.

The ancient array was powered by one hundred and eight spirit stones, which had now disintegrated into dust, clearly indicating their stored pure energy had been completely depleted. Further testing and verification revealed that the stones powering this formation were the extremely rare Heavenly Spirit Stones.

This meant the driving force required one hundred and eight Heavenly Spirit Stones. The realization caused Lei Dong to gasp sharply. He was certainly familiar with Heavenly Spirit Stones, but he had never dared contemplate acquiring one.

They were not only exceedingly rare but also obscenely expensive. Theoretically, the spiritual energy contained within a single Heavenly Spirit Stone was only about dozens of times that of a top-grade spirit stone, albeit purer. Following the traditional hundredfold escalation, a Heavenly Spirit Stone should cost around one hundred million low-grade spirit stones.

But reality dictated otherwise. Due to their scarcity and lack of open market availability, even an exchange would likely demand at least three hundred top-grade spirit stones for a single piece.

That amounted to a staggering three hundred million low-grade stones! A typical wealthy Nascent Soul cultivator could bankrupt themselves and still not afford one. Lei Dong considered his own fortune substantial, yet selling all his assets would barely net him a few dozen Heavenly Spirit Stones.

How could this not shock him? He inwardly cursed the powerful elder who had designed the formation; the design was absurdly extravagant. Setting up the array with thousands upon thousands of top-grade spirit stones would have been far more sensible.

In truth, Lei Dong could hardly blame that elder. Sustaining time manipulation and spiritual energy conversion for such an extended duration demanded an astronomical amount of energy. While top-grade spirit stones were adequate, they inevitably fell slightly short in terms of energy abundance and purity. Moreover, during the ancient or primeval eras, resources were plentiful, and even Innate Spirit Treasures could be found everywhere; thus, there was no shortage of Heavenly Spirit Stones.

However, the current age was far from those times; resources had become critically scarce. For Lei Dong to gather one hundred and eight Heavenly Spirit Stones was a feat comparable to scaling heaven itself.

Yet, having that goal provided direction, and Lei Dong did not consider the Grotto-Heaven Paradise useless. At the very least, the cultivation gained during these four-plus years had already proven highly lucrative for him. The old fiend Xue Mo had smoothly advanced to the mid-stage of Nascent Soul and continued cultivating in the Grotto-Heaven Paradise; though still far from the late stage, he was no longer a typical mid-stage Nascent Soul expert, his true essence even richer than Tian Mo’s.

Lei Dong’s master, the Ancestor of Ten Thousand Ghosts, had been on the cusp of breaking through to Nascent Soul. Utilizing the opportunity, he broke through to the early stage and, supported by Lei Dong’s massive resource influx and relentless cultivation within the Paradise, catapulted straight to the mid-stage.

Though Lei Dong had initially hoped his master would reach the mid-stage, he never expected the old man to achieve it in one continuous burst. Faced with the result, he was momentarily speechless. Even with the Paradise’s support, achieving such results in such a short time was nothing short of miraculous.

What Lei Dong didn't realize was that the Ancestor of Ten Thousand Ghosts was cultivating with fierce determination fueled by pent-up emotion. First, he felt his own weakness made him unable to adequately protect his disciple and his lineage. Second, as the respected master of Lei Dong, Wan Yan, and Qing’er, the exceptional achievements of his disciples, while a source of immense pride, also generated a powerful sense of urgency. While surpassing one's master embodies the saying, "Blue emerges from indigo, yet is bluer than indigo," the Ancestor felt it tarnished the prestige of the Ten Thousand Ghosts. Thus, the old man had truly pushed himself. Of course, such results were also due to the Ancestor’s long-accumulated foundation; despite his previous lack of raw power, his understanding of cultivation and the world was profound.

As for the Twin Heroes of Yin Sha, they were naturally gifted individuals of rare talent. Coupled with Lei Dong’s unsparing resource allocation and the Paradise’s unique effects, they spent the fifty-plus years single-mindedly focused on strengthening themselves in seclusion. Not only did they logically break through to the early Nascent Soul stage, but they also utilized spare time to continually refine their techniques and spells, elevating their overall combat prowess significantly. Their desperate efforts stemmed from their near uselessness against the powerful Heavenly Ghost Emperor during the last battle in the Nine Nethers, where they had inadvertently become a burden.

This realization spurred the intensely proud Twin Heroes to silently vow to achieve true strength.

Regarding Qi Feifei, her cultivation was diligent, but her innate talent was slightly inferior to the Twin Heroes. However, she possessed her own advantage: mastery of the Su Nu Cauldron Art. This technique offered little enhancement to direct combat strength but was exceptionally potent for general cultivation, especially dual cultivation. Originating from the Joyous Union Sect, she excelled in all forms of intimate cultivation techniques. She stealthily sought out the secluded Lei Dong and initiated some clandestine activities.

It was precisely through these methods that she managed to push through and reach the early Nascent Soul stage precisely as the array failed.

Lei Dong, unfortunately, fared the worst. Possessing only elixirs valued in the hundreds of millions of spirit stones, he could not employ his Demonic Emperor Transformation for relentless, pressure-cooker cultivation. At his current level, he required at least hundreds of thousands, if not a top-grade spirit stone, per day. Over fifty years, even if he were minced and sold, the earnings wouldn't cover such astronomical costs.

Consequently, even with his frequent, secret dual cultivation with Qi Feifei, his cultivation only reached the late Golden Core stage, just shy of the peak.