Moving to the drier side of the cave, Xiao Yu began her own rigorous training. She didn't have the luxury of a water scroll or a master's guidance, so she relied on raw repetition. She extended her hands, calling upon the frosty-silver Dou Qi within her Dantian.
Slowly, she started shaping her ice.
At first, she merely formed crude, jagged spikes. She pushed her concentration, refining the edges, condensing the molecular structure of the ice until the spikes were as sharp and clear as polished glass. She shaped daggers, small shields, and intricate, floating lotus flowers. She maintained the constructs until her Dou Qi reserves were completely finished, her arms shaking from the exertion.
Once drained, she would drop into a meditative stance by the dying bonfire, aggressively circulating her Qi method to pull the dense worldly energy back into her body, recovering her strength. Then, the moment her Dantian was full, she would stand up and begin to practice again.
As time passed, the hidden cave behind the waterfall became a silent, isolated crucible. Both of them existed entirely in their own worlds, grinding relentlessly through their respective stages of power, united only by the steady, deafening roar of the falling water.
A full day passed before Yoriichi could even force the two opposing energies into a tense, agonizing stalemate. Slowly, painstakingly, he finally managed to start absorbing the ginseng's essence, pulling it into his Dantian molecule by molecule.
But the true nightmare had only just begun.
Even though the Mystic Aqua Spirit Ginseng was inherently gentle, the raw power contained within it was an extreme Yin element, making it the absolute, mortal enemy of his extreme Yang foundation. The moment the azure energy was forced to circulate alongside his solar energy, Yoriichi's body became a battlefield for two ancient gods.
His muscles underwent a terrifying, excruciating process of biological quenching. The scorching heat of his Sun Breathing would violently expand and tear his muscle fibers to their absolute breaking point, only for the abyssal cold of the Aqua Spirit Ginseng to instantaneously contract and freeze them. They were being brutally destroyed and rebuilt, over and over again.
The extreme temperature differential was so severe that the sweat and moisture in his body, along with fine beads of blood seeping from his strained, bursting capillaries, instantly vaporized right off his skin. He was continuously shrouded in a ghastly, swirling reddish-white mist, making it appear as though his very flesh was evaporating into the damp cavern air.
Internally, it was far worse. His vital organs were screaming on the absolute verge of total, catastrophic failure.
According to the ironclad laws of Dou Qi, Fire and Water could never coexist. His heart, the biological engine of his fiery vitality, spasmed wildly, skipping erratic beats as the freezing aquatic energy flooded the surrounding arteries. His lungs felt as though they were inhaling molten lava and exhaling shards of jagged ice. The sheer pressure threatening to detonate his Dantian was astronomical.
'Hold,' Yoriichi commanded his failing vessel.
His consciousness was entirely detached from the blinding physical agony, coldly watching his own body tear itself apart and knit itself back together through the lens of the Transparent World.
'A supreme sword cannot be forged solely with fire, nor can it be tempered without water,' Yoriichi's internal monologue echoed with an ancient, unyielding resolve. He forcefully utilized the insane anatomical theories from the Battle Through the Heavens scroll, desperately using his Dou Qi as a rapidly depleting buffer to keep the opposing elements from directly touching his heart.
'My body is the blade. The Sun is the hammer. The Ocean is the anvil. If these elements wish to destroy me, they must first break my will. And my will is absolute.'
Through sheer, inhuman willpower forged over decades of slaughtering demons, he kept the chaotic circulation moving. He refused to let his organs fail. He forcefully dictated the rhythm of his own beating heart, refusing to let the opposing elements dictate his death.
Days turned into a week. The pile of dry wood slowly dwindled. The mental strain of micromanaging the elemental war within his own flesh was pushing his soul to the absolute precipice of madness.
Then, a sudden, powerful shift occurred in the cavern's atmosphere.
The extreme, suffocating pressure within his Dantian finally reached critical mass. Yoriichi, who had been sitting as still as a petrified statue within his bloody mist for seven days, suddenly drew a massive, vacuum-like breath.
BOOM!
A muffled, concussive shockwave rippled out from his body, acting as a desperate release valve for the internal pressure. The shockwave blew the misty spray of the waterfall violently backward. He had broken through entirely silently. His Dantian expanded violently, crossing the threshold from a Three-Star to a Four-Star Dou Zhe.
The ambient worldly energy in the hidden place went into a frenzy, violently rushing into his body to fill the newly expanded storage capacity, bathing his scorched and frozen organs in pure, revitalizing life-force.
The breakthrough saved his life, reinforcing his vessel just enough to contain the war. Yet, Yoriichi did not open his eyes. He did not stop. He simply continued his agonizing, millimeter-by-millimeter absorption.
More time passed. The relentless, torturous cycle of cultivation consumed him.
Then, exactly a month after they had first entered the hidden cave, a profound, impossible anomaly occurred deep within Yoriichi's internal universe.
He directed his inner vision toward his violently spinning Dantian. There, amidst the roaring, hyper-compressed milky-white cyclone laced with scorching crimson-gold sparks... a foreign entity had successfully taken root.
Yoriichi could sense it clearly. It was a single, microscopic strand of brilliant, azure blue sparkle.
It was infinitely small, but it was there. It was stable. It was not evaporating. It was the absolute, undeniable seed of the Water attribute, successfully forced into a vessel that was never meant to hold it.
He had survived the biological quenching. He had forced the heavens to rewrite his anatomy. He had defied the ironclad laws of the continent.
Yoriichi didn't smile. He didn't jump up in excitement or shout in triumph. His stoic, ancient heart simply acknowledged the success, knowing exactly what horrific price his body had paid to achieve it.
Maintaining his absolute, monk-like tranquility, Yoriichi ignored the lingering, phantom pains of his shattered muscles and calmly continued his cultivation meditation, nurturing the fragile azure seed within the roaring furnace of his soul.