Hearing this, Luan Baifeng reached out and grabbed a basin-sized chunk of black stone, then tossed it to Yang Kai. "You can try it yourself. I can't say for sure either way."
Yang Kai caught the black stone and hefted it, finding it surprisingly heavy. He gave it a light squeeze, but not a single mark appeared on its surface.
It was worth noting that his strength was now truly immense — any ordinary mineral subjected to such force would at the very least crack, if not crumble entirely. Yet this black stone was clearly no ordinary material; it was extraordinarily tough.
His spiritual sense surged as Yang Kai attempted to probe the stone's interior, but under his perception, the black stone completely blocked out his spiritual sense, making it impossible to discern whether anything was hidden inside.
Yang Kai let out a surprised hum. As a Sixth-Order Open Heaven cultivator, his spiritual sense was formidable, yet even that was sealed off by this black stone. What on earth was this thing?
After a brief moment of contemplation, Yang Kai activated the World-Destroying Demon Eye, and his left eye immediately transformed into a golden vertical pupil.
Looking through it, he finally perceived something different. Inside the black stone in his hand, a hazy, indistinct mass of pale yellow energy could be seen churning.
This sight sent a jolt through Yang Kai's heart — the World-Destroying Demon Eye was useful!
Though he couldn't make out the precise details within the black stone, he could confirm that there was indeed something inside this particular piece, and it appeared to be an Earth-attribute material. As for what grade it was, there was no way to tell — the stone would need to be dissolved first.
The World-Destroying Demon Eye possessed the ability to see through illusion, and together with the Purgatory Black Pupil, the two were known as the twin forbidden secrets of the Myriad Demon Heaven, an extremely profound eye technique. Even within the Myriad Demon Heaven, only the most elite core disciples were qualified to cultivate it.
Yang Kai had obtained this World-Destroying Demon Eye back when he was still very weak, long before he had encountered Ti Zheng. At the time, he had known nothing of these secrets.
But since it was one of the Myriad Demon Heaven's twin forbidden secrets, the World-Destroying Demon Eye naturally possessed its own wondrous properties. Where spiritual sense could not perceive the stone's interior, the Demon Eye could pierce through the illusion to reveal the essence within.
That said, Yang Kai's mastery of the technique was still lacking, so he could only make out a vague impression. If someone who had truly cultivated this technique within the Myriad Demon Heaven were to examine it, they would likely see far more clearly.
His movements had not gone unnoticed by Luan Baifeng. The woman regarded him with some surprise. "You cultivate an eye technique as well?"
"What about it?" Yang Kai dismissed the World-Destroying Demon Eye and glanced over at her.
Luan Baifeng slowly shook her head. "Nothing. Did you see anything?"
"No," Yang Kai replied casually. Luan Baifeng might have noticed his eye technique, but she almost certainly didn't recognize it as a secret art of the Myriad Demon Heaven, and he had no intention of explaining further.
However, to verify the information he had just gathered, Yang Kai promptly channeled his own World Force to envelop the black stone in his hand.
The black stone rapidly shrank.
With his Sixth-Order Open Heaven cultivation and World Force far more abundant and dense than that of an ordinary Sixth-Order cultivator, his speed in dissolving the stone was naturally absurd.
The basin-sized black stone in his hand completely vanished in less than the time it took an incense stick to burn, and a pale yellow crystal slowly materialized in its place.
Luan Baifeng looked over in surprise. "A Fourth-Order Earth-attribute material. You've got decent luck!"
Yang Kai tossed the pale yellow crystal casually in his hand and asked, "What are the odds of finding cultivation resources inside these black stones?"
"Very low," Luan Baifeng replied softly. "When you're lucky, maybe around thirty percent. When you're unlucky, it might not even be ten percent."
"Thirty percent is still too low," Yang Kai shook his head slowly. Seven out of ten black stones containing nothing at all — how much time and manpower would that waste?
"That's why I say every single piece of cultivation resource in Black Prison is hard-won. Did you really think this place was littered with treasures just waiting to be picked up off the ground?" Luan Baifeng scoffed, then paused and frowned. "What exactly are you looking for? You've already taken every last bit of Black Prison's accumulated stores over the years. Isn't that enough?"
Yang Kai shook his head slowly. "Not enough. I still need more Sixth-Order Yin-Yang attribute materials."
Luan Baifeng frowned. "If you're using them for your own cultivation, you could just refine Fifth-Order resources instead. The speed would be slower, but Fifth-Order materials aren't that hard to come by. Why are you so fixated on Sixth-Order?"
She clearly assumed Yang Kai was gathering all these Sixth-Order resources for his own refinement and cultivation.
Yang Kai smiled. "For my own cultivation, Fifth-Order would certainly suffice. But what if someone needs these materials to advance to Sixth-Order Open Heaven?"
Luan Baifeng froze for a moment, then her eyes widened. "That's impossible! How could your Void Land possibly have that many people capable of advancing directly to Sixth-Order?"
Every individual capable of advancing directly to Sixth-Order was someone with the potential to reach Eighth-Order Open Heaven — they were exceedingly rare. Even among the Cave Heavens and Blessed Lands, such talents appeared perhaps once in a thousand years. Yang Kai had already stripped her of enough Sixth-Order Yin-Yang attribute materials to satisfy the needs of ten people advancing, and that still wasn't enough?
Yang Kai offered no explanation. Words were useless here. Now that Luan Baifeng had fallen under his command, she would understand soon enough once she witnessed the Void Land's true depths for herself — he wasn't just blowing hot air.
"Stop standing around and give me a hand. Let's start dissolving these black stones and see if we can find what I need," Yang Kai called out. Though over a dozen Open Heaven realm cultivators were already at work, their efficiency was lackluster. When it came to dissolving black stones, the higher one's cultivation, the faster the process — it was likely related to the abundance and density of one's World Force.