More than a month later, deep within the Yin-Yang Cavern, Han Li stood in a vast wind fissure, hands clasped in seals. Dozens of golden flying swords spiraled around him, constantly moving up and down, effortlessly scattering countless black, moth-like creatures that surged toward him. Each of these moths was only a few inches in size, with a sleek black body; when their wings fluttered, they sent out fine, sharp gusts of wind that were easily deflected by the golden light of the swords. As the moths kept advancing, one after another, as if endless, Han Li grew increasingly impatient. Suddenly, he reached down with one hand and grasped his spiritual beast bag at his waist, raising it into the air. Instantly, golden blossoms burst forth from the bag, spreading out in all directions. These were Han Li's golden insect swarm—the Phagocytic Golden Insects. As soon as the black moths came into contact with the insects, they began to plummet from the sky, quickly falling behind. Seeing this, Han Li gathered most of the flying swords and stepped forward, heading deeper into the cavern. Since this was a wind fissure, the surrounding black winds were exceptionally strong. Even with his powerful consciousness, he could only reach a few dozen feet ahead. However, once freed from the disturbance of the moths, he no longer feared this limitation. As he approached the center of the wind cavity, a blue glow flashed in his pupils, and his gaze instantly pierced through the surrounding black winds, allowing him to see clearly all around. Upon taking a quick survey, he paused, slightly surprised, and then changed his direction. After walking only twenty or so feet, he raised his hand again, and a translucent moonstone, wrapped in green spiritual energy, floated into the air, illuminating the area clearly. Under the soft milky glow, a black crystalline stone the size of a human head was half-embedded in the opposite wall, only half exposed. What was astonishing was that as the stone emitted a deep, dim light, countless black moths continuously emerged from within, rushing fiercely toward both韩立 and the prominent moonstone—yet all were intercepted and consumed by the golden insects along the way. At once, countless moths fell from the sky, only to vanish into nothingness before reaching the ground. "It's the third one now, though this one has somehow managed to summon its own yin-ming moths using the ambient yin qi—quite unusual," Han Li murmured to himself. At the very moment the crystal stones were lifted, the fierce, turbulent winds around them diminished by half. The black moths that had been engaged in fierce combat with the gold-devouring insects flashed with a deep black glow and then dissolved into mist, blending seamlessly into the wind and vanishing. Han Li paid no attention to this phenomenon. Although the two crystal stones ahead were not as large as this one, they had also been discovered in the same wind-vortex region, and would likewise exhibit this effect once extracted. Initially, Han Li had been amazed by this occurrence, but now he simply took it for granted. Since the last time he encountered the elderly man from the Fu family and renewed the purple-azure divine light, he had been operating independently from Bai Yaoyi. Without her accompanying him, Han Li found himself free to fully employ a wide array of techniques. In recent days, as he had gradually ventured deeper into the heart of the cavern, he had encountered numerous high-level ghost creatures during his explorations—yet under the combined power of his flying sword and the divine, protective lightning, they were all utterly eliminated. Even the啼魂 (Tí Hún) beasts had not been summoned once. As for exploration speed, Han Li was nearly twice as fast as the others. While the others finished exploring one branch corridor, he had already completed two. However, it was no surprise that, despite the renowned reputation of the Yin-Yang Cavern, few high-level cultivators had ventured there before—though not entirely unexpected. Having delved so deeply, they had found only ordinary minerals and a few damaged artifacts or法宝, with no significant discoveries. It was only after Han Li, in his pursuit of a fleeing ghost, accidentally entered a modest wind cave and discovered a black crystal stone that he began to take an interest in these previously unexplored wind caves. After all, in such a place where the阴wind is fierce, Yin herbs could not survive. Moreover, entering the wind caves would immediately intensify the consumption of both the supporting Purple-Yuan Divine Light and one's own cultivation energy—naturally, no one would willingly seek such hardship. Han Li, protected by his Divine-Defying Thunder and sustained by a thousand-year elixir that replenished his energy, had no such concerns. In fact, he was particularly intrigued by this crystal, often delving deep into it for inspection. These black crystals he had never seen before, nor had they been mentioned in any of the ancient texts he had previously consulted. At first glance, they resembled black marrow drills, yet they were fundamentally different. The black crystals were far less hard than black marrow drills, and they did not contain magical energy—instead, they seemed to be a peculiar wind-type crystal formed over the long years of steady accumulation within the yin chambers, yet rich in yin energy. However, such black crystals were not common. After searching through dozens of wind chambers, he had only encountered three so far. The first two were roughly fist-sized and lacked the ability to transform into ghostly beings—far inferior to the one before him. After gazing at this crystal, which no longer responded, for a while with narrowed eyes, Li Han finally raised his hand and affixed several sealing talismans to it. Only then did he place the black crystal into a large jade box and store it in his storage pouch. Then he thoroughly searched the vast wind cavity, ensuring nothing had been missed, before stepping out and returning to the passage. After walking several hundred paces forward and exploring another smaller cavern, the passage gradually narrowed. Eventually, a stone wall sealed by ice appeared ahead. Han Li sighed, but still took a few steps forward and raised his hand, sending a streak of azure light toward the wall. "Pffft!" The light pierced the wall several zhang deep before vanishing. Han Li did not stop there. He placed his palm on the wall and simultaneously scanned the stone with his divine awareness. After a moment, confirming the wall was solid, free of mechanisms or seals, he immediately turned around and ascended into the air, heading back along the path. Having already cleared the way once, his speed returned to several times faster. Although he still knew the full extent of the yin-yang cavern, the variety of spectral beings they had encountered suggested that they were now approaching its very core. Yet no one has yet spotted the traces of that Yin Zhi Ma, which has begun to irritate Han Li. Having hastily prepared the San Yan Fan and taken the risk to descend into this realm, he absolutely doesn't intend to return empty-handed. Though he has never personally attempted the challenges of advancing from mid to late Metamorphic Stage, he can well imagine the difficulties involved. One can only think of the rare talents among cultivators who reach mid-stage advancement—how few, indeed, succeed in further breaking through to the next level! Across the southern heavens, only three such individuals have achieved this. While the number of Metamorphic Stage late-stage cultivators in the Great Jin has grown, compared to the vast number of immortal sects and cultivators, they remain exceedingly rare—fewer than one in ten thousand. Thus, even with the Dian Feng Pei Yuan Technique at his disposal to help overcome his current bottleneck, Han Li still has no confidence whatsoever in whether he will truly attain the late Metamorphic Stage. Now that such a Pill capable of refining the Yuan Yin has emerged, he naturally refuses to let it pass. If, this time, he failed to find the Yin Zhi Ma within the Yin-Yang Caverns, he would surely have to find a way to secure the formula for the Pei Ying Dan from the wealthy elder. Though the chances seemed slim, as long as he had the formula, he would surely search elsewhere for the Yin Zhi Ma—after all, the world could not have only one gathering place of Yin Qi, namely the Yin-Yang Caverns. Han Li paid no attention to this, instead bowing slightly and immersing his consciousness into the jade scroll. "I've located the trail of the Yin Zhī horse—this truly is good news!" After a moment, with a smile on his face, Han Li withdrew his consciousness from the scroll. Then, he flipped his palm, and a pale white array disc appeared in his hand. With a single finger touch, the disc flashed with a green light, its surface becoming as smooth as a mirror, while four distinct, colorfully glowing points subtly pulsed upon it. Han Li briefly scanned the positions of these glowing points before swiftly closing the disc and launching forward at twice his usual speed. Half a day later, Han Li arrived at a bustling intersection where two figures—one a Yuan-named young man and the other an Fu-named elder—sat cross-legged facing a passage leading east. The purple-azure pearl floated steadily above the elder's head. "Master Yuan, have you found that object?" Han Li asked lightly as he descended from the purple light. "Very good. The Yin Zhi Ma is indeed within this passage. However, this spiritual creature is exceptionally clever, and I alone cannot catch it. Therefore, I shall temporarily seal off the exits here, and await all of you." The Han named Yuan chuckled, a hint of excitement visible on his face. "That's excellent. As long as we know where this creature is, capturing it will simply be a matter of time." Han Li nodded with a smile. "Chang Sister and Bai Friend are a bit farther away, so we'll need to wait a little longer. With everyone gathered, our chances will be much stronger." The wealthy elder likewise beamed with satisfaction. Upon hearing this, Han Li immediately felt relieved and sat down on the spot. After waiting for several hours, the black-robed woman and Bai Yao Yi arrived as well, both deeply delighted upon receiving the confirmed news. Without any delay, they first set up several simple magical arrays at the entrance and then all proceeded together into the eastern passage. Yet no one knew, just shortly after they had taken off, a sudden glow emerged from beneath the ground at this intersection, and then three black, dry corpses slowly rose into view. Each of them had hollow chests and bone-thin bodies, yet their eyes glowed with cold green light, fixed impassively upon the direction where Han Li and the others had vanished.