Not long after, the cauldron lid opened. A fierce heat surged upwards, yet the Ming Dan did not float out. Looking closer, it was actually being entangled and held fast by three strands of green emerging from the cauldron walls. If Nie Kong hadn't given prior instructions, the little fellow would have surely couldn't resist devouring it already. Qie Kong couldn't help but smile, quickly reaching out to grasp the "White Snow Pill."

This Ming Dan was as its name suggested; its surface radiated a snowy white luster, and through the naked eye alone, not a trace of the dark shadow within the pill could be discerned. Nie Kong brought the Ming Dan close to his nose and sniffed a few times. Just like the batch refined previously, the fusion degree was only sixty percent.

After a brief contemplation, a wisp of death aura condensed at the tip of Nie Kong’s finger, sharp as a blade, slicing the White Snow Pill into two halves. The center was indeed inky black.

Nie Kong scraped a tiny bit into his mouth to taste, but detected nothing unusual. Frowning slightly, Nie Kong directly placed the two halves of the Ming Dan into his mouth.

"Xiangxiang..."

With just a thought, the medicinal cauldron vanished. Immediately, the little fellow, following Nie Kong's directive, coiled the "White Snow Pill" back into the Lingshen Aperture. Then, it deliberately separated the black matter from the two halves of the Ming Dan and performed an "Aroma Identification" technique specifically on it.

Unfortunately, no matter how hard the little fellow tried, the mass of black substance showed no change whatsoever. After several minutes, the little one finally gave up trying to discern its medicinal properties, drooping its stem, leaves, and roots while continuously whimpering, its tone laced with deep frustration.

"What is this thing, that even Xiangxiang’s Aroma Identification is ineffective?"

Logically, whether it was a refined medicine or a natural herb, it should not escape the "Aroma Identification." But now that Xiangxiang couldn't handle it, could it be... that it had already moved beyond the category of mere medicine? Nie Kong was filled with suspicion.

Earlier, while still in the medicinal cauldron, the moment those black substances manifested, Nie Kong had sensed an extremely pure death aura emanating from them. At that time, Nie Kong hadn't paid much attention; the medicinal herbs from the Underworld Soil all contained death energy, especially the black ones, and since death energy was also used for refining, it was natural for pure death energy to appear in the Ming Dan.

However, recalling it now, Nie Kong suddenly felt something was slightly off.

After letting the little fellow consume the "White Snow Pill," Nie Kong took out the remaining mid-grade Ming Dan and sliced it in half. This Ming Dan was black from outside to in, but at its very center was a small clump whose color was visibly several times more concentrated than the surrounding material.

Evidently, every time a Ming Dan formed, this small clump of black matter would emerge.

Yet, Nie Kong turned it over and over in his palm, rubbing it for a long time, without detecting any anomaly. That small black mass had perfectly integrated into a whole with the surrounding medicine; the only difference between the two was the concentration of the death energy contained within.

This single point was insufficient to reveal the secret within.

"I still need to find a way at the moment the Ming Dan takes shape," Nie Kong’s mind raced swiftly. After a brief moment, Nie Kong’s expression shifted, and he silently summoned the medicinal cauldron, which reappeared before him, manifested by the little fellow. The second small medicine bag was opened next.

This was already the third attempt at refining the "White Snow Pill," and Nie Kong’s movements were even more practiced, with the entire process taking slightly less time. In less than fifteen minutes, the medicinal power of most of the Gui Long Hua had merged with that ball of snow-white energy, and the lingering wisps of Gui Long Hua, under the impact of the heat, adhered to the surrounding snow-white energy, beginning their final fusion.

"Now! Xiangxiang!"

The instant the last wisp of Gui Long Hua medicinal power vanished, Nie Kong roared internally. The little fellow, fully prepared, responded with an "Aiya-ya" without hesitation. Over a dozen fine green strands rushed out from the surrounding cauldron walls.

In an instant, the green strands touched the just-formed Ming Dan. At this moment, that strange black substance once again surfaced within the Ming Dan.

The little fellow’s movements were not delayed in the slightest; the green strands plunged directly into the Ming Dan.

In the blink of an eye, all the black matter gathered towards the center of the Ming Dan. But just as they were about to complete their condensation, the dozen or so strands of natal medicinal power, which had been waiting, suddenly struck—entangling them all and pulling them out from the Ming Dan.

"Boom!"

The moment the black matter departed, the Ming Dan exploded violently, scattering into a cloud of powder throughout the cauldron. This situation signified...

The refining process had failed! Fortunately, the "White Snow Pill" was only a low-grade Ming Dan, and the explosion occurred precisely when the Ming Dan was forming. Most importantly, the cauldron currently in use was manifested by the little fellow, so the shockwave generated by the reaction was not intense; the cauldron only shuddered twice before returning to calm.

"Without those things, the Ming Dan actually struggles to form? Not good," Nie Kong’s heart skipped a beat, and he quickly shifted his focus back to the cauldron. Seeing that the black substances were still entangled by the dozen green strands and hadn't vanished due to the Ming Dan's explosion, Nie Kong secretly breathed a sigh of relief. Then, with a thought, the cauldron lid sprang open, and Nie Kong reached in. Seconds later, looking at the round black substance in his palm, a satisfied look dawned on Nie Kong’s face. For Nie Kong, this time... the White Snow Pill... refining failure, did not affect his mood in the least; merely extracting those black things counted as success.

After observing for a moment, Nie Kong calmed his mind, enveloping the black matter with death energy, closing his eyes to sense it carefully.

"Huh?"

Nie Kong's eyes snapped open, and he let out a surprised gasp.

The clump of black matter contained pure death energy, but this death energy was not purely inert; it was imbued with a rich vitality!

Death energy containing vitality... In the past, such a phenomenon would have greatly astonished Nie Kong, but now he was quite used to it. Never mind the "Underworld Spirit Valley" of the War Clan, even the death energy in the "Dead Spirit Cave" of Fubo Mountain contained immense vitality.

The main reason Nie Kong was surprised now was that this phenomenon had appeared within a Ming Dan.

In Nie Kong’s understanding, Ming Dan also contained vitality, but this vitality was not condensed into a clump; it was dispersed throughout the entire medicine. Furthermore, that vitality was not derived from death energy but was inherent to the Ming Dan itself. Just like the spirit medicines Nie Kong had refined before, only when the spirit medicine inherently possessed vitality could Nie Kong stimulate it, making the vitality more vigorous.

Turning the thought over, Nie Kong picked up the two halves of the sliced mid-grade Ming Dan again.

"Death energy containing vitality when the Ming Dan forms; no vitality once formed. If the vitality within the death energy diffused the moment the medicine formed, it could indeed interfere with the Ming Dan's fusion degree... But after removing these things, the result wasn't an increased fusion degree, but refining failure... That's rather strange! There must be other secrets hidden within."

After pondering for a long while, Nie Kong closed his eyes again and continued to probe the clump of black matter, but he found nothing else for a long time.

Nie Kong frowned slightly, then suddenly activated the "War God Star Seal" spiritual technique.

As the Ming Star inside his body flickered, the black substance in his palm rapidly shrank at a rate visible to the naked eye. In less than ten seconds, it shrunk from the size of a flower bud to the size of a green bean.

At this point, Nie Kong suddenly discovered that the vitality contained in the death energy of the remaining black matter had decreased significantly. After another moment, when the clump of matter was only the size of a sesame seed, there were no signs of any vitality existing in the death energy.

However, bizarrely, Nie Kong sensed a feeling similar to "Spirit Treasure Essence" from the remaining black matter.

That was...

"Origin?"

According to the little spirit Qingyue, the "Spirit Treasure Essence" he cultivated was closer to the origin of heaven and earth than Wood Ancestor's! His "Spirit Treasure Essence" evolved from mutated wood spirit energy merged with vitality and death energy, yet this tiny bit of material in his palm, containing only death energy, could actually allow him to sense an aura approaching the origin of heaven and earth?

Nie Kong suddenly felt an urge to laugh.

But as the slightest smile touched his lips, Nie Kong froze. Wood Ancestor's "Spirit Treasure Essence" contained no death energy, only exceptionally massive vitality, yet it still possessed the aura of origin. Why shouldn't this little thing, which only possessed death energy, do the same?

Thinking this way, Nie Kong instantly sobered up.

"...Aiya-ya!"

The little fellow’s voice rang out ceaselessly, accompanied by a minuscule thread of green light emerging from Nie Kong’s right palm, tentatively touching the small black speck. It seemed the little fellow had coveted it for a long time, but dared not act without Nie Kong’s permission.

Nie Kong was currently studying this trace of origin power; how could he give it up for consumption?

"Eat it!"

With no other choice, he tossed the last two halves of the mid-grade Ming Dan into his mouth. The little fellow cheered happily, and the green thread immediately retracted from his palm.

It seemed the only thing in the Ming Dan that attracted the little fellow was this trace of death energy close to the origin of heaven and earth! He hadn't expected Ming Dan to contain such a thing. If the little fellow ate more Ming Dan, it would likely advance to the sixth tier in no time!

Nie Kong smiled secretly and continued to circulate his spiritual technique.

Absorbing this origin power, which consisted only of death energy, only required running the "War God Star Seal" with his main body; it didn't need to be combined with the "Yin-Yang Devouring Spirit Art" of his second avatar. Relatively speaking, it was much simpler, though the absorption speed did not increase accordingly.

Several minutes later, the sesame-seed-sized portion of origin power completely vanished from his palm. Sensing the changes in the death energy within his body, Nie Kong nodded secretly.

It was indeed as he had guessed: absorbing this kind of origin power increased the speed of cultivation faster, but the amount of death energy origin was too small. Relying solely on refining medicine to extract and absorb the death energy origin was actually less effective than cultivating in the Underworld Spirit Valley.

"What influences the success or failure of Ming Dan refinement must be this death energy origin, along with the vitality contained within the death energy..." Nie Kong mused inwardly. Just as he was considering whether to go to the "Pill King Tower" to get some herbs and try again, a series of loud footsteps sounded from afar, approaching from outside the courtyard...

...