It seems this ghostly soldier, refined from mere Yin Souls, is indeed an exceptionally malleable species. Not only can they be commanded in depth through divine sense, allowing for temporary reshaping into any desired form, but their initial manifestation shape can also be fixed during the initial refining process by manipulating the array formation.

Thus, it appears that the ghost soldiers forged via the Yougui Banner (Nether Ghost Banner) are not limited to being mere combat units; a variety of auxiliary ghost soldiers could be developed. The more Lei Dong considered it, the more excited he became. Once inspiration struck, he truly recognized the endless variations possible with ghost soldier materials.

The creation of an energy "storage tank" was paramount, as this component directly concerned the combat effectiveness of the ghost soldier contingent. Designing such a storage tank ghost soldier was remarkably simple; one only needed to draw inspiration from the previous design of the Big-Belly Cannoneer.

In just two or three days, the design proposal underwent numerous refinements. Following this, Lei Dong instructed the artifact spirit to integrate this design into the Yougui Banner and subsequently manufactured one hundred units at once.

Gazing upon the hundreds of new troop types floating before him, Lei Dong felt a surge of emotion.

These ghost soldiers, which Lei Dong termed "Gas Storage Ghosts," retained absolutely no trace of their original Nether Ghost form. Their shape was entirely that of a plump, spherical mass, about the size of a football. However, when contracted, the wall of the ghost body was incredibly thick, leaving only a space about the size of a ping-pong ball in the center.

At this moment, the Gas Storage Ghosts were in an empty state. Lei Dong attempted to envelop one with Youming Ghost Qi (Nether Ghost Qi). As if by instinct, it extended a wide mouth from its "body" and began to devour the Youming Ghost Qi ravenously.

The rate of consumption was astonishing. Vast quantities of Youming Ghost Qi were sucked into its interior, and one could visibly witness its football-sized body rapidly swelling. It continued to expand until it reached the size of a large water vat before ceasing its feeding.

The Gas Storage Ghost was now fully saturated with Youming Ghost Qi. Its thick "flesh wall" had thinned to the gossamer quality of a cicada's wing, containing an immense volume of Youming Ghost Qi compressed to extreme density. Through its now-thin body, one could clearly observe the dense, ink-like Youming Ghost Qi, almost pressed into a liquid state.

Lei Dong wiped a bead of cold sweat from his brow. This "Gas Storage Ghost," designed without consideration for any other ability besides maximizing wall thickness and pressure resistance, possessed an excessively powerful storage capacity. The Youming Ghost Qi just stored within it had cost him one-thousandth of his Xuanyin True Essence to convert.

Lei Dong further tested retrieving it into the Yougui Banner and then releasing it; the deployment and retrieval were seamless, and the stored quantity remained undiminished.

Lei Dong tried another experiment: directing a fully loaded Big-Belly Cannoneer to unleash a blast at Xuan Yuanzi from a distance. After the attack, the Cannoneer returned to replenish its Youming Ghost Qi. The Gas Storage Ghost merely expelled a portion of its stored Youming Ghost Qi, which was more than enough to fully power the Big-Belly Cannoneer.

What a treasure, truly a magnificent thing. The Youming Ghost Qi stored within just one of these Gas Storage Ghosts was sufficient to fuel ten shots from the Cannoneer's Nether Fire Shells. This meant that merely a thousand such units could completely drain all the power held within his own body.

Under normal circumstances, exhausting one's True Essence was inconsequential. By consuming high-grade spirit stones, taking elixirs, and meditating, he could slowly replenish the primal power within his body, the Xuanyin True Essence, a process that only required one day.

It was clear that in his spare time, Lei Dong could continuously manufacture vast numbers of Gas Storage Ghosts to stockpile his reserves of Youming Ghost Qi.

Having temporarily resolved the energy reserve issue, Lei Dong turned his attention to researching the strategy of elite forces. Lei Dong had played with the Wan Gui Banner (Ten Thousand Ghost Banner) for decades, repeatedly testing both the cannon fodder horde strategy and the elite troop strategy, finding distinct advantages and disadvantages to each.

The advantages of the Ghost Sea tactic were: first, overwhelming numbers. Second, the death of many units was not a cause for heartache. Finally, in certain situations, the Ghost Sea tactic held a distinct advantage.

The elite troop strategy, however, caused the Ghost Sea to shrink drastically, making it difficult to achieve scale. In terms of total combat power, it was also significantly weaker than the Ghost Sea, and the loss of even a single unit would be painful. For instance, using the suppression method of the Yougui Banner, if Lei Dong aimed to evolve all his ghost soldiers to the Nascent Soul level of combat power, even with the combined effort of the Demon Dragon and Lei Dong, they could likely suppress a maximum of eight such entities. Yet, if those seven or eight Nascent Soul-level ghost soldiers contended directly against seven or eight hundred thousand low-tier ghost soldiers, the latter would undoubtedly emerge victorious, likely with more than half remaining. Furthermore, losing one Nascent Soul-level ghost soldier would be devastating; how much resource would it take to acquire such a unit? The cost was unimaginably high.

This was even considering Lei Dong's abnormal divine sense and the Yougui Banner. Consequently, ordinary Ghost Cultivators who used the Wan Gui Banner rarely employed the elite troop strategy; they couldn't afford it, nor could they manage it.

However, high-tier ghost soldiers also had their merits: strong single-unit assault capability, making it effortless to assist their master in killing cultivators of the same rank. Their comprehensive attributes were infinitely superior, and their speed offered significant advantages in both pursuit and evasion, allowing for highly flexible tactics. This was because every single high-tier ghost soldier could be precisely controlled via divine sense to execute extremely nuanced tactical coordination, unlike the Ghost Sea tactic where a high-level enemy could escape with relative ease.

For Lei Dong, both approaches had their merits. But for the average cultivator, there was no question—the Ghost Sea strategy was the obvious choice.

In fact, even for Lei Dong, the Ghost Sea tactic held a significant advantage. This was because the enemies he typically faced were exceedingly high-level. Taking Xuan Yuanzi as an example, the time it took him to slaughter a Golden Core stage cultivator was not significantly different from the time it took him to crush a low-tier ghost soldier. Conversely, suppressing a Golden Core stage entity with the Yougui Banner required thousands of times the divine sense power needed for a low-tier ghost soldier.

However, the Yougui Banner seemed to possess a unique quality. Under its potent refinement, an ordinary Yin Soul could achieve the capabilities of the late Qi Refining stage. But in reality, the divine sense expenditure required to control it was no different from a common, trashy Fierce Ghost—less than even the early Qi Refining stage.

This suggested a strong operational flexibility. If a ghost soldier that required only the divine sense consumption of the early Qi Refining stage could exert the actual combat strength of the peak Nascent Soul stage, Lei Dong might grit his teeth and bankrupt himself to procure two or three such units.

This meant Lei Dong needed to conduct some experiments. First, he covertly acquired four high-grade potential spirit ghosts and one top-grade potential spirit ghost using the Soul Devouring Tower. Then, discreetly, he refined them into several soldier types, with the top-grade spirit ghost being forged into a Big-Belly Cannoneer.

This method of using spirit ghosts possessing spiritual root aptitude to forge ghost soldiers appeared outwardly identical to ordinary ghost soldiers, with no discernible difference in aura fluctuations. However, in essence, they possessed a fundamentally different nature.

Ghost soldiers refined from trashy Yin Souls required the slow and utterly wasteful process of devouring souls and flesh to advance. Ghost soldiers with spiritual root aptitude, although their spiritual intelligence potential was completely destroyed during refinement, still retained some benefit from the spiritual root. They could still evolve through the inherent talent of devouring flesh and blood.

Of course, this type of evolution was vastly inferior to that of a Natal Ghost Servant, requiring massive amounts of resources just to maintain their progression. Naturally, they could also be cultivated first into something like a Wild Ghost General before being refined, but this path offered no advantage over the former, as a refined Wild Ghost General would only reach the level of an ordinary Foundation Establishment stage ghost soldier.

Furthermore, in front of Xiao You, Lei Dong preferred not to push matters to excessive cruelty.

Then Lei Dong began feeding them. The Yougui Banner still contained a surplus of the previous generation of Nether Ghosts, which were now obsolete. These were perfectly suitable for feeding and catalyzing the evolution of the newly forged soldiers.

Despite the formidable power attributed to the Nether God, who granted the Ghost race their unique (tūnshì, devouring) evolution talent, through the massive consumption of Yougui, the top-grade Big-Belly Cannoneer was the first to evolve in terms of level, gradually reaching the standard of early Foundation Establishment. This calculation was based solely on the level of divine sense consumed to control it; in actuality, measurements showed its overall capability was already infinitely close to the peak Foundation Establishment stage.

This greatly delighted Lei Dong, although it was consistent with logic. The most primitive ghost soldiers, fundamentally speaking, were less than early Qi Refining stage, yet they could exhibit the actual capabilities of late Qi Refining stage.

This could only be attributed to the sheer might of the Minyan Yougui Banner (Nether Flame Nether Ghost Banner). Lei Dong’s life-threatening endeavors for it, including sacrificing the Nine Nether Ghost Flame and Chaos Refined Iron, had not been in vain.

Lei Dong continued to feed and catalyze their development.

The previous generation of Yougui were rapidly consumed, while the top-grade Big-Belly Cannoneer, due to its exceptionally superior spiritual root, took the lead and advanced to the early Golden Core stage. Its physical size had not changed significantly; it remained like an ugly, clumsy, fat black worm.

But in reality, it had completely transformed. From ascending to early Qi Refining, then early Foundation Establishment, and finally early Golden Core, it had evolved across three major tiers. Its ghost body was now covered in scale-like armor plating, and the Youming Ghost Qi within its big belly had been compressed by its large torso until it became liquid, resembling a vat of translucent ink, containing surging energy. At a glance, it appeared ferocious and menacing.

Lei Dong tested it and found that the overall ability of this Golden Core stage Big-Belly Cannoneer was roughly equivalent to that of the late Golden Core stage. However, its flight speed was not fast, only comparable to an ordinary early Golden Core stage cultivator.

Next, Lei Dong eagerly began the most crucial test for it: an assessment of the power of the Youming Cannon Shell. It was important to note that the divine sense resources consumed just to maintain this single Golden Core level Big-Belly Cannoneer were equivalent to the consumption required for several thousand low-tier Big-Belly Cannoneers.