Inside the mysterious grand formation, Yang Kai extended his spiritual sense to probe his surroundings but couldn't glean much. However, since this formation had been specifically developed for this purpose, it did possess a sealing effect.
As for whether it would actually work, a trial would tell.
Yang Kai immediately activated the Purifying Light, opting not to use high-grade Yellow Crystals or Blue Crystals, limiting himself to Fifth-Order ones in case the experiment failed and to avoid waste.
Soon, a ball of white light resembling a small sun materialized in Yang Kai's palm. Under his control, it remained condensed and did not dissipate, brilliantly dazzling to the eye.
As everyone watched, Yang Kai tossed the small-sun-like ball of white light outward. In an instant, the white light flooded the entire formation, only to be blocked by the luminous barrier, sealed within.
Yang Kai waited in silence. Whether this formation could securely contain the Purifying Light over the long term was critical to his subsequent plans — he could not afford any sloppiness, and had to confirm the feasibility of this approach.
His spiritual sense monitored the white light's condition without pause. Outside the formation, Feng Ying and the others were also closely watching, though the formation's interior was now flooded with blinding white light, bathing Yang Kai's figure within and rendering him somewhat hazy and indistinct.
As time passed, Yang Kai's expression gradually brightened. He realized his earlier thinking had been correct — the Purifying Light was a manifestation of energy, and being energy, it could indeed be sealed. The formation crafted by Fan Xun and the others had achieved precisely this.
The Purifying Light was contained within the formation, unable to dissipate or diminish, and could be preserved over the long term. This meant that as long as human warriors afflicted by the Ink Force were brought inside, the excess Purifying Light remaining after the Ink Force was expelled would not go to waste.
Grain by grain, the pile grows — in the long run, this would undoubtedly conserve a significant amount of Yellow Crystals and Blue Crystals.
"Uncle-Master Fan, it's ready," Yang Kai called out. Fan Xun, who was controlling the formation from outside, heard him and immediately shifted his hand seals. A crack appeared in the formation's luminous barrier.
However, before Yang Kai could step out of the formation, some of the Purifying Light contained within had already leaked out through the opening.
Once Yang Kai exited and Fan Xun sealed the formation once more, a glance inside revealed that the Purifying Light within had noticeably diminished.
Yang Kai turned back to look, and the elation on his face gradually faded, his brow furrowing.
He had overlooked something — this formation did possess a sealing effect and could indeed preserve the Purifying Light, but every time it was opened, the formation would expose its gateway, and the stored Purifying Light would inevitably leak out through the opening.
A small loss here and there might not matter, but what about ten times, a hundred times? If this plan were to be implemented, every warrior afflicted by the Ink Force would need to enter the formation. Opening it once upon entry and once again upon exit meant two instances of Purifying Light loss per person — that was far too wasteful.
Unless the formation could remain sealed at all times, but if it was sealed, afflicted clansmen would be unable to enter.
This was a thorny problem.
Fan Xun and the others had clearly noticed this issue as well, each one frowning in thought.
Yang Kai looked toward him. "Uncle-Master Fan, do you have a method of improvement?"
Fan Xun considered for a moment before replying, "We could add a condensing restriction. That might do the trick."
The others nodded slightly, and one said, "Makes sense."
"Then I'll have to trouble all of you."
The formation masters immediately set to work. Adding a restriction on top of the existing formation was far from simple — the restrictions within a formation were all interconnected, meaning that altering one element could affect the entire structure. To add a single restriction required sweeping modifications to the whole formation, ensuring it continued to operate flawlessly while achieving all the intended effects.
Fan Xun and his colleagues huddled together, bustling ceaselessly — sometimes deploying formation discs and formation flags, sometimes leaning in to whisper amongst themselves, and occasionally even arguing red-faced over minor disagreements.
Yang Kai had no way to assist, so all he could do was wait. From time to time, afflicted clansmen came seeking help, and he naturally dispatched them quickly, purging the Ink Force with the Purifying Light.
The clansmen who came for aid had no idea what Fan Xun and the others were busy with. As a general rule, once treated by Yang Kai, they would immediately depart and return to the battlefield to fight the Ink Clan.
Such fighting would only cease when the Ink Clan retreated.
After several days, a new formation took shape. Though Fan Xun and the others were high-level cultivators, they were visibly weary — not from physical exhaustion, but from mental fatigue.
Everyone understood that Yang Kai's work here was of paramount importance, and they had all given it their absolute best effort, expending enormous mental energy in the process.
Just as before, Yang Kai stood inside the formation and activated the Purifying Light, letting it flood the interior, ready for another test.