"I also need to teach them the proper, uncorrupted way to initiate their upper-realm training. A flawless foundation is the single most important thing in a newly ascended spirit master’s life. It is the most crucial, yet tragically the most neglected first step, one that fundamentally alters the future potential of any master."

He knew better than anyone how even the most subtle, seemingly insignificant mistakes made during these beginning stages would reflect massive, irreversible changes in their power ceilings later on.

What made the situation far more serious was the incredibly narrow window of time he and the other masters possessed to get this right. They didn’t just have a strict spirit-grade limit restricting the use of these advanced foundation-laying methods; they were also bound by a ruthless time limit imposed by the laws of the plane.

Their physical bodies would completely lose the malleable, receptive state brought about by the ascension process within a week. They wouldn’t receive a single drop of benefit if they tried to initiate these secret training methods even seven days after their arrival. Therefore, he absolutely needed to return with the cores and kickstart their training sessions at once.

Keeping that pressure firmly in mind, William knew there wouldn’t be another miraculous chance to collect such a massive number of high-grade cores or raw resources once their training officially commenced.

The window to initiate the training session was short, but the gruelling training period itself was anything but brief. He knew it would take them roughly a month or two of absolute isolation just to lay down the right spiritual foundations.

"It might seem like a painfully long period of stagnation at first glance," he muttered to himself as his figure blurred across the dark plains, heading back toward the glowing horizon. "But when you look at the grander picture of living for decades or centuries here in the upper realm, a couple of months looks like nothing at all.

In fact, if the elite masters of this realm had a chance later in life to repeat this exact foundation training and gain the same flawless results, many would willingly bleed themselves dry to get it. But the laws of reality are cruel; they wouldn’t be able to achieve it even if they spent many years trying to undo their past missed chance."

William didn’t stop at just collecting the glowing spinal cores. Eventually, he had successfully harvested the cores of almost all the fallen shadow monsters residing near the outer margins of the artificial hell he had created.

He knew his limits; he couldn’t venture any deeper past a certain point without being vaporised by the intense, escalating heat, nor could he foolishly try to run around and directly assassinate the live monsters currently drawing near the chasm. The sheer volume of the incoming stampede was too high.

Therefore, all he could do now was to actively roam the wider surrounding area, looking for as many raw resources as he could find and stacking them away into his storage ring as much as his inventory capacity would allow.

He knew that the current window of safety he possessed wasn’t incredibly long, but it wasn’t terribly short either. According to his past knowledge and precise estimates, if the volatile ore mine continued to unleash high-density spirit power at this current, roaring rate, it would take at least three full days for the truly scarier, high-tier predators to get attracted to this spot from their faraway territories deep within the forbidden zone.

On the other hand, digging the defensive trench wouldn’t take his followers longer than a single day. In fact, it would perhaps turn out even shorter than that, thanks entirely to the newly enhanced physical physiques of his guild masters after absorbing their first upper-realm cores.

Consequently, the timeline of the base construction didn’t worry him in the slightest. Instead, he utilised this precious time to move around the periphery, searching for any exotic resources that might help his people advance their spirit grades much better and faster after the completion of their upcoming foundational training.

At the same time, he kept his eyes peeled for raw structural materials he could use to lay down a few robust defensive lines around their designated safe zone.

He knew better than anyone that getting interrupted in the exact middle of their critical foundation training session was an unavoidable risk in a place like this. Rather than panicking, he had to deal with that grim possibility with calm acceptance and meticulous, preemptive preparations.

"If I recall the layout of this region correctly, the main native monsters occupying the lower ecosystem of this zone are these mindless shadow ones," William muttered, carefully navigating a rocky ridge.

"But the real troublesome anomalies we need to watch out for are the Thunderous Birds... They always descend without a single shred of warning, landing like lightning bolts directly from the high skies and bringing a devastating tempest of thunder along with them.

We cannot completely avoid their aerial attacks, as I don’t possess the specific anti-air arrays to block them entirely, but I do know their fundamental elemental weakness... Luckily, I already possess the exact right element to use against them."

William knew that under standard elemental laws, lightning was widely considered the absolute nemesis of the darkness element.

However, he also knew a high-level cultivation secret: darkness could completely withhold, absorb, and ground the destructive properties of lightning if it was properly amplified and stabilised using the correct conducting materials and structural settings.

To pull off this elemental inversion, he needed to look for either a very specific type of dense, spirit-absorbent wood from local trees or a few rare types of conductive ores that could naturally store and heavily augment the raw darkness element he commanded.

"And on top of that, I need to find a heavy material that I can successfully use to propel the darkness element up to higher altitudes, allowing us to actively attack anything flying up there," he mused, recalling everything he had read or learned about the behaviour of those avian predators.