Supreme Immortal Aperture, Small Central Continent.
Fang Yuan had been making preparations for several months (in Immortal Aperture time), and they had reached the critical moment!
In the center of a square-shaped pond sat a small pavilion in the middle of the water.
At Fang Yuan's will, a Gu Insect drifted slowly toward the pavilion.
This Immortal Gu was perfectly round like a pearl, the size of a goose egg. Countless shimmering light patterns swirled across its surface in endless transformation, resembling ten thousand lotuses blooming at once, or clouds churning in the sky.
It was the Blood Capital Immortal Gu!
This Gu had been independently created by the Langya Earth Spirit, drawing upon certain Blood Path Gu recipes from Treasure Yellow Heaven.
The Blood Capital Immortal Gu could protect a portion of immortal materials or Gu Insects during a Gu Immortal's refining process. If the refinement failed, those materials or Gu could be recovered afterward through the Blood Capital Immortal Gu.
The Blood Capital Immortal Gu had originally been only at the Sixth Transformation, but not long ago, through Fang Yuan's relentless efforts, it had been successfully elevated to the Seventh Transformation using the Hairy Man Refinement Great Formation.
The Blood Capital Immortal Gu drifted down to land gently on the pavilion's rooftop, where a golden seat had been built just for it.
In Fang Yuan's mind, thoughts surged like an ocean tide. Though this step appeared simple from the outside, in truth, to successfully complete this final phase, Fang Yuan had been expending as many as a hundred thousand thoughts every single moment!
Click.
With a soft sound, the Blood Capital Immortal Gu settled firmly into place upon the golden seat.
Immediately, Fang Yuan's Immortal Essence was consumed. The golden seat produced a powerful suction force, locking the Blood Capital Immortal Gu securely in position.
The Blood Capital Immortal Gu burst forth with a rich, crimson light.
The blood-colored glow flowed like liquid, cascading down from the pavilion's roof and spreading across its surface, dyeing the originally white jade pavilion a deep vermilion red.
After flooding the pavilion, the blood light continued to spread outward until it covered the entire, previously still surface of the pond.
The pond water turned vivid red, as though it were blood itself.
Faint ripples began forming on the surface. With the sound of rushing water, waves lapped against the outermost square stone walls — only to vanish instantly upon contact, and in the blink of an eye the surface became calm and ripple-free once more.
The Four-Element Regret Blood Refining Pool had finally been successfully constructed!
Fang Yuan wiped the sweat from his forehead. After maintaining intense concentration for the better part of a month, he could finally relax.
He immediately felt an overwhelming wave of exhaustion seep out from the very depths of his bones.
"My mental energy is completely drained, and I've consumed a significant amount of Immortal Essence as well," Fang Yuan acknowledged clearly. His spirit felt listless, and all he wanted was to throw caution aside and collapse into a deep sleep.
That was exactly what he did.
He slept for two full days and two full nights.
His mental energy had finally recovered.
Fang Yuan immediately sent out a thread of divine sense to inspect the Four-Element Regret Blood Refining Pool.
After a thorough examination, he nodded with satisfaction. There were no flaws whatsoever.
Constructing this refining pool had taken every ounce of his effort — he had exhausted himself body and mind!
But the price had been worth it. The Four-Element Regret Blood Refining Pool he had built through such sacrifice was absolutely a pinnacle masterpiece of the Refinement Path in the current world.
Fang Yuan had brilliantly integrated multiple Refinement Path-related Gu Houses and formations — the Regret Pool, the Refining Furnace, and the Hairy Man Refinement Great Formation — merging them all into a single design and devising the blueprint for the Four-Element Regret Blood Refining Pool.
The Regret Pool was one of the Three Great Pools under heaven, standing alongside the Heavenly Pool and the Wine Pool, renowned across the Five Regions and etched into history. When a Gu Immortal refined Immortal Gu here and succeeded, the imprint of that success was preserved within the pool. Should the Immortal Gu later be destroyed, the Regret Pool could be activated, harnessing the power of a Time Tributary together with the preserved success imprint to refine the Gu once more — the success rate typically reaching fifty to sixty percent.