In the spacious and well-lit cave, Xiao Yan gazed at a large wooden basin placed before him, filled with clear, transparent water. Beside the basin stood a simple wooden rack, laden with various herbs—seeming to number no less than several dozen. It had taken Xiao Yan nearly three days to locate all these medicinal plants. "Give me the Earth-Core Body-Quenching Milk," the herbalist said, extending his hand after checking that all the required herbs were present. At the sound of this, Xiao Yan promptly handed over the items. The herbalist took the jade bottle containing the Earth-Core Body-Quenching Milk, gently weighed it in his hand, then opened the lid. Immediately, a delicate jade-like mist drifted out, gradually gathering at the bottle's mouth and lingering there for a long time. The old pharmacist deeply inhaled the mist and felt a gentle warmth flowing through his soul, smiling and marveling, "Indeed, it's no wonder this spirit essence, drawn from the earth's power, is so pure and potent—it's precisely this refinement that enables such miraculous effects as purifying the marrow and strengthening the bones." After praising it, he tilted the jade bottle slightly and carefully poured ten drops of liquid—each resembling a jade bead—into the wooden basin. As soon as the last drop touched the water, the liquid inside the bottle had diminished by nearly a quarter. The old physician focused intently on the changes in the liquid's color, and casually remarked, "The energy of the Earth-core Quenching Body Milk is too vast. With your current strength, it's impossible to ingest it directly. Therefore, you must resort to this method. Even then, it must be harmonized with other medicines to achieve the effect of purifying the marrow and refining the bones. Otherwise, if you force it down, not only will the marrow purification fail, but even your life itself might be washed away." Xiao Yan blushed slightly, wondering if his body wasn't that frail. "Give me the 'Incense Candle Grass.'" Without paying attention to Xiao Yan's quiet murmurs, the old physician, after observing the liquid's color and concentration, gently instructed. Upon hearing this, Xiao Yan quickly reached out and picked up a small red plant resembling a candle from the wooden rack, then presented it to the old physician. As the old physician held the 'Incense Candle Grass,' a crisp, pale flame formed in his palm, rising gently like a frozen flame. He casually tossed the former into the flames. In just a moment, the fragrant candle grass withered swiftly and eventually transformed into a single drop of red liquid under the intense heat of the Bone Spirit Cold Flame. After several rounds of refining the ground red liquid with the Bone Spirit Cold Flame, the herbal master lightly flicked his finger, and the liquid settled into the wooden basin. As the drop of red liquid entered the basin, the surface of the water, originally as clear and jade-like as ever, subtly darkened to a faint red hue. "Seal Lotus Fruit," the herbal master murmured softly, and Xiao Yan hurriedly retrieved the fruit from the wooden shelf. After a few minutes of refining, the Seal Lotus Fruit also transformed into a drop of green liquid, which fell into the basin, adding a delicate hint of green to the water. "Snake-Loose Blossom." "Buddha's Flame Root." "... A continuous stream of different herbs emerged from the elderly physician's mouth, and as each sound was uttered, the herbs on the wooden rack rapidly diminished. After one hour, dozens of herbs had completely transformed into liquids of varying colors and were poured into the wooden basin. Once the final herb was fully refined, the elderly physician exhaled in relief, gazed at the now vibrant, multicolored surface of the water in the basin, and nodded contentedly to Xiao Yan beside him, saying, 'Remove your clothes and enter the water to meditate. Continue until the water returns to clear.' Xiao Yan stared in astonishment at the colorful liquid, formed by the harmonious fusion of the essences of dozens of herbs, and deeply admired the elderly physician's extraordinary skill in refining the herbs. This mastery, however, was not dependent on innate talent but rather stemmed entirely from accumulated experience and a deep understanding of the diverse effects of various herbs." "Be careful after entering, although the 'Earth-Heart Body-Infusing Milk' has been tempered by these herbs and its effects have become more gentle, its inherent energy has not diminished—it has actually increased. Thus, during your cultivation, you may experience some discomfort. But once you endure it, you'll reap significant benefits," the herbal elder said, smiling as he clapped his hands. Hearing this, Xiao Yan could only nod helplessly. Immersed in the vibrant liquid, he clearly sensed the immense energy within it. Even before entering his cultivation state, the energy was already seeping into his body, causing a tingling, prickling sensation—like ants crawling across his skin. He vigorously shook his head to suppress the discomfort. Over the years, he had endured countless hardships, so these sensations no longer posed much of a hindrance. Sitting cross-legged in the wooden basin, he formed the cultivation hand seals and gradually closed his eyes, his breathing becoming calm and steady. After a while, the tingling sensation softened and faded, and Xiao Yan entered his cultivation state. By the side of the wooden basin, the herbal elder watched Xiao Yan enter his state of cultivation, smiled gently, and said softly, "Though washing the marrow and refining the bones offer tremendous benefits, the hardships along the way are no small matter. If one endures through them, the path will be smooth; if not, not only will the efforts be in vain, but the body's meridians may suffer damage from the powerful energy surge, resulting in a situation where the outcome is ultimately unsatisfactory. Though there are risks involved, how else can one advance far on the path of cultivation without courage and boldness?" At the very moment the bubbles rose, Xiao Yan's body suddenly trembled. He could feel that countless streams of pure energy within the water were being drawn by some unseen force, forcefully pouring through the slightly open pores across his entire body! The volume of energy rushing in was so immense that Xiao Yan even sensed a growing tightness and discomfort in his skin. Yet, despite his sensation, the pure energy did not slow down—it surged with even greater intensity. Eventually, as there was no room for it to seep through, the energy began to surge randomly beneath his skin, causing visible ridges and bulges to form across his body—like tiny serpents writhing beneath the surface, a sight both striking and alarming. While Xiao Yan was naturally aware of this outward appearance of terror, at that moment he could only fully concentrate his mind, constantly monitoring every subtle change within his body. The vibrant, multicolored energies flowing into his body ignored Xiang Yin's commands entirely, instead purposefully rushing toward various bones within him. Any bone they encountered instantly transformed into a radiant, multicolored hue, and beneath this shimmering color, Xiang Yin could faintly sense something penetrating the bones and blending seamlessly with the bone marrow. Unable to stop or influence these energies in any way, Xiang Yin could only watch as an increasing number of his bones turned into this vibrant, multicolored state. Within less than ten minutes, nearly all of the bones in his body were completely enveloped in this colorful glow, creating a strikingly strange and ethereal appearance. As Xuanyin found himself slightly puzzled by these energies' actions, a sudden, sharp tremor surged in his heart. He sensed as though a blaze had ignited within his bones, a deep, searing pain rapidly spreading through his marrow and eventually reaching every corner of his body. Clenching his teeth, the figure seated in the wooden basin trembled subtly, a peculiar rosy hue emerging on his skin. Cold sweat poured over his forehead, accumulating densely until it cascaded like a light rain down his face, dripping into the basin. Now he finally understood why the old doctor had mentioned some discomfort—yet… wasn't this discomfort a bit too intense? The herbal elder, standing outside the wooden basin, couldn't help a flicker in his eye as he watched Xiao Yan's actions. He then sighed softly and said, "Young one, you must hold on. If you succeed in purifying your marrow, you'll greatly simplify the process when you eventually ascend to the Battle King stage."