Inside the cave, observing the medicinal liquid in the wooden basin suddenly spinning rapidly, the herbal master's eyes flashed with astonishment. With his expertise, he was clearly able to sense the powerful suction surging forth from Xiao Yan's body. He murmured softly, "This young one truly intends to make a breakthrough to the Grand Battle Master level. With this momentum, it's indeed a promising opportunity. Yet the energy required—how vast it is!" The medicinal liquid in the basin spun swiftly, releasing waves of pure, refined energy that continuously flowed into Xiao Yan's body as he practiced. As this pure energy was consumed, the originally vibrant, multicolored liquid began to fade rapidly. At this pace, it wouldn't take long before the immense energy within the liquid was entirely absorbed by Xiao Yan. While absorbing energy from the medicinal liquid, the intense internal suction also forcibly draws and incorporates energy from the surrounding celestial and terrestrial realms. Although this energy drawn directly from the天地 is noticeably more fragmented than that within the medicinal liquid, it is far superior in volume and inexhaustible. Thus, with this dual approach, the robust energy flows continuously into the body, tirelessly replenishing the crystalline core, which otherwise appears as an ever-deepening abyss. Yet although Xiao Yan absorbed energy at an exceptionally swift pace, the sheer magnitude of energy required for each rank advancement was overwhelming. Ordinary individuals typically needed prolonged accumulation to achieve such breakthroughs. Xiao Yan, however, aimed to advance two levels consecutively in a single effort—requiring an energy volume that was truly staggering. Even with his rapid absorption, the fist-sized combat crystal remained utterly unfulfilled, merely appearing slightly more lustrous than before. As time passed, the momentum of Xiao Yan's recent advancement began to wane, especially after he fully absorbed the last trace of refined energy from the medicinal elixir. Without this immense energy support, the energy drawn directly from the heavens and earth proved insufficient to sustain the crystal's consumption. Consequently, the robust energy flowing into Xiao Yan's body gradually diminished. At the moment of ascending to a higher stage, the most critical issue is an insufficient supply of energy midway—this would directly lead to the failure of the ascension. However, as Xiang Yan was currently in the process of cultivation, he had no alternative but to continuously circulate his internal techniques, striving to strengthen the energy he could draw from the heavens and earth. Though the energy of the heavens and earth was inexhaustible, the fragmented energy, after being refined within his body, could only be absorbed in a relatively small quantity. For Xiang Yan, at this very moment, such a quantity was utterly insufficient—like a drop of water in a vast river. With the infusion of this "Earth-Core Body-Infusing Milk," the previously clear water once again transformed into a rich, jade-green hue, thick and almost impermeable, with dense mist swirling gently within the wooden basin. The pure, potent energy surged once more, filling the space abundantly. For Xiao Yan, this sudden addition was truly a lifeline—this renewed influx of pure energy finally banished the fatigue within his body. With a mere mental effort, the pure energy flowed like a steady spring stream through his meridians, continuously circulating and ultimately being channeled into the battle crystal, bolstering its capacity with each contribution. This drop of "Earth-Core Body-Quenching Milk," introduced midway and unblended with any other medicinal agents, carries a notably more potent and assertive energy. Fortunately, at this stage, Xiao Yan's body has already undergone a prior marrow purification, significantly strengthening his constitution. Thus, while the potent energy initially causes a subtle stinging sensation—though not as intense as the earlier scorching pain—it is nearly entirely tolerable. The drop delivers an impressive amount of energy to Xiao Yan. However, the energy required for the next rank advancement is so formidable that it is almost inexplicable—exceeding the cumulative energy of all levels within this stage. Even though this single drop of "Earth-Core Body-Quenching Milk" is exceptionally robust, after an hour of relentless absorption, the originally jade-like medicinal liquid in the wooden basin begins to grow noticeably more pale and diluted. With a slight squint at the now fainter herbal infusion in the wooden basin, the herbal master shook his head in resignation. After assessing the current state of Xiao Yan's energy flow, he hesitated slightly before once again dripping in two drops of "Earth-Core Body-Quenching Milk." To achieve the rank of Douling, ordinary individuals typically needed years of steady accumulation—some even spanning several years—demonstrating the immense energy required to overcome this threshold. Without such celestial and terrestrial treasures as the "Earth-Core Body-Quenching Milk," Xiao Yan would have been lucky to reach the peak of a Nine-Star Doushen, and a direct breakthrough to Douling would have been nothing short of a dream. Fortunately, this exceedingly rare "Earth-Core Body-Quenching Milk" happened to be in his possession. Indeed, it was a blessing of fortune. Each drop of "Earth-Core Body-Quenching Milk" carries an astonishingly potent energy—energy that could easily match the accumulated reserves of an ordinary person over six months. The initial ten drops had mostly been devoted to refining Xiao Yan's physical form, and only a fraction—just one-tenth to one-twelfth—of the energy remained and was absorbed by him. The drop of "Earth-Core Body-Quenching Milk" administered without prior blending was completely absorbed, yet even its energy alone was insufficient to propel Xiao Yan to the Dou Ling level. Now, however, the two additional drops that Master Yao is pouring in have finally become the final splash that fills the last vessel of the water tank! The spirit continuously guides the energy along the pathways of the "Burn-Decision" technique, flowing like a steady stream of vehicles on a high-speed highway, roaring past, and ultimately surging directly into the Dou Crystal. No matter how deep the chasm, it will eventually be filled. Though the energy required for advancement is staggering, it is now being rapidly replenished with the addition of three drops of "Earth-Core Body-Nourishing Milk." At the very moment when the medicinal liquid in the wooden basin completely transformed into clear water, the powerful suction emanating from Xiao Yan's body suddenly vanished with remarkable abruptness. His body trembled slightly, and his pores gradually contracted, sealing all internal energy within, preventing any further leakage. Within the aura vortex, a combat crystal the size of a fist shone like a brilliant sun, emitting a warm, intense light that permeated the entire vortex. The final surge of energy flowing through his meridians also entered the vortex and ultimately flowed into the radiant crystal. "Buzz!" "As the final surge of energy was infused, the rhombic battle crystal suddenly trembled slightly, emitting a low, resonant hum that gradually settled and echoed within the vortex. Subtly, a delicate, rhythmic sound began to rise within the vortex—on closer listening, it sounded remarkably like the beating of a heart, an unusually profound phenomenon. With this rhythmic pulse, the light emanating from the crystal grew and dimmed in an irregular pattern. To Xiang Yin's focused awareness, he was astonished to observe that the crystal, which had initially appeared somewhat irregular, was gradually becoming smoother and more spherical, like a bead. As the crystal's body rounded out, its surrounding angular facets began to protrude unexpectedly, forming a striking resemblance to a sea urchin covered in long, sharp spines. Counting carefully, there were precisely nine such long, pointed spines on the sea urchin-like structure." The glow of the spiky crystal fluctuated in intensity, and with each variation in brightness, the rhythmic pulsing sound from within—like a beating heart—resonated once more, as though a vibrant heart lay nestled within the spiky structure itself. As the rhombic crystal fully transformed into the spiky form, the intensity of its internal glow grew increasingly rapid, and so too did the pace of its heartbeat. "Thump, thump..." The low, deep resonance gradually echoed within the body, eventually aligning perfectly with the natural rhythm of Xiao Yan's own heartbeats. At the very moment when these two heartbeats merged into a seamless unity, the spiky crystal within the vortex suddenly trembled, and a powerful wave of energy surged forth from its core! This energy wave flowed unimpeded through the vortex, the meridians, the internal bones, and finally through the skin, where it erupted with sudden force. Inside the cave, Xiao Yan's eyes suddenly snapped open, sharp and intense light bursting forth like tangible substance. A powerful aura surged from within him, and as it poured out, he lifted his head sharply, emitting a clear, resonant roar filled with robust combat energy—crashing through the cave like thunder.