Feiyin sat cross-legged before the still-warm cauldron, the freshly formed yin refining pellet resting in his palm. The rune on its surface pulsed softly, like the steady heartbeat of a slumbering moon. Without hesitation, he placed it between his lips and swallowed.
It slid down his throat with the dense chill of an ice cube, settling heavily in his stomach. Almost immediately, he felt the yin rune within begin to unfurl, its power uncoiling in slow, deliberate waves. That cold, pure force seeped outward, threading through his meridians until it reached his conception meridian. There, under his precise guidance, the energy began refining his essence qi.
The difference was startling. When he had first refined yin energy naturally from the world, even at his best and after a whole night he had only managed to temper perhaps one percent of his essence qi to an acceptable degree. But this pill- its potency struck like moonlight piercing an endless sea. He could already feel that it would refine over sixty percent of his total essence qi, and to a far higher purity, which, for someone with a single qi nexus, could have completed their yin refining entirely.
In addition, as a young man, he had expected the natural limitations of his constitution to hold back the purity he could achieve, for men were naturally attuned toward yang while women's bodies could nurture and generate a far purer yin force without strain.
A male body could only refine yin to a certain degree before it risked causing imbalance or even harm, just as a woman overly steeped in yang would. Yet here, with the effect of the rune and his opened conception meridian, his body accepted the inflow of pure yin without conflict, almost as if the barriers between his constitution and the energy had been lifted. The sensation transcended his expectations, brushing against a state he could only describe as pure yin- the serene, untouchable light of the moon, cool yet embracing, distant yet gently illuminating every corner of his being.
Hours passed as he worked, letting the potency sink deeper. The changes were unmistakable. Within his qi nexuses, his refined essence qi gathered into the faint outline of a brilliant full moon, its light spilling down to bathe the cyclone below. Wherever that light touched, the remaining unrefined essence qi began to change, aligning itself to match the same purity- continuing the refinement even without the pill's direct influence.
It was then that Feiyin recalled something he had once read: at high levels of yin refinement, the purified qi could sometimes take on distinct forms, each shape reflecting the refinement's quality and depth. The full moon was known among ancient treatises as a rare sign, close to the elusive state called the "Supreme Yin Refining the Form," a stage where yin energy reached such harmony that it embodied an image of perfection.
The sight stirred a quiet thrill in him, for this was no mere byproduct- it was a signpost on a path few ever walked. The effect even persisted after the last threads of the pellet's energy were spent, leaving him quietly astonished at its lasting nature.
His body, too, shifted under the pill's touch. Muscles unwound into a comfortable looseness, even as his internal organs hummed with renewed vitality. He became acutely aware of his digestive and reproductive systems, their activity heightened- a realization that drew a faint, embarrassed frown to his face. But the greatest transformation was within his soul.
A soul was naturally closer to yin, and when the refined essence qi reached his mind's eye, it enriched his very being. When he had initially reached fifty percent refinement, his spiritual sense abruptly doubled, stretching from twelve hundred meters to nearly twenty-four hundred, already surpassing most yang-refining cultivators. Not only that, but the clarity was sharper, and he even felt his ability to control his spiritual sense, and by extension his essence qi, become steadier.
When at last he exhaled, a thin plume of frost left his lips as an amusing thought surfaced in his mind.
'Yue would probably take it to make ice cream.'
Chuckling to himself, his gaze steadied as he shifted to the next task.
The aptitude pill.
He leaned back, eyes narrowing in thought. Aptitude was a vast tapestry- woven from comprehension, the rate of essence absorption and conversion, the capacity for storing essence qi, and the ability to wield it efficiently. For him, one aspect had stood above the rest: the meridians. When he had opened the final two of the one hundred and eight meridians, the world itself had baptized him, strengthening his entire body and meridian network. That singular event had paved the way for his later feats- three dantians, faster qi nexus rotation, and the opening of every acupoint in his body.
If he could grant even a fraction of that advantage to his family and companions, the impact on their future cultivation would be immeasurable.
Yet the task was daunting. Enhancing the toughness, elasticity, and size of meridians was no simple matter- even for a runic alchemist. He sifted through his knowledge, weighing which ingredients could bring which effects.
Yet the more he thought, the more he realized a single pill would not suffice. As the effect was too diverse, which he felt could not be precisely encapsulated within a single rune.
'Why not break it down then?'
Three pills. That was the answer.
One to broaden the meridians, allowing greater flows of essence qi. Another to harden them, so they could withstand higher pressures without injury. And a third to grant them elasticity, ensuring they could adapt to changing flows and elemental strains.
He began at once, drawing out an additional storage pouch reserved for surplus ingredients he had prepared for the occasion.
For the first pill, he ground life-green spiritual herbs rich in growth essence, selecting them as the main component to encourage expansion and vitality, then balanced them with a handful of auxiliary herbs that would temper the growth, preventing uncontrolled surges.
For the second, he blended dense yellow minerals steeped in earth essence as the main stabilizing core, pairing them with lighter, flowing nectar to maintain an even flow rather than a rigid block.
For the third, he chose a rare Sky River Reed, pale blue and supple, grown in places where water currents shifted unpredictably, using it as the primary agent for flexibility, and complemented it with small buds of a Spirit Mountain flower whose gentle essence helped bind and harmonize the mixture.
Finally, hours later, he held the fruits of his labor in his hands. Three runic pills-green, yellow, and blue- each bearing a distinct rune: one like a branching vine, one like interlocking stone, and one like flowing water. The air around them shimmered faintly, each radiating its own subtle rhythm.
Wiping sweat from his brow, Feiyin felt the abundant essence qi still flowing through his meridians, a quiet fire urging him forward. He glanced at the remaining ingredients, lips curving into a small smile.
Now that the formulas were proven, it was time for mass production.