The Immortal Physician's Transmigration: Miraculous Rejuvenation

Ye Yuanchen and his companions struggled to venture deeper into the dark castle. The surrounding darkness was so thick and tangible, it seemed to be desperately trying to hinder their progress. Every brick and stone in the castle exuded an evil aura, and the eerie runes flickering on the walls were like sinister eyes, watching their every move.

"Everyone must be careful. This dark castle is becoming increasingly sinister, and the dark power is constantly increasing," Ye Yuanchen warned in a low voice. The Spirit Void Holy Sword in his hand flickered with light, yet it still stubbornly carved out a patch of light in the darkness. The power of the sacred artifact flowed slowly along the sword, infusing Ye Yuanchen with a continuous stream of strength.

Mu Wanyue gripped the Spirit Whip tightly, pink and rainbow-colored light swirling around her body, as if she were clad in a magnificent suit of armor. "This darkness seems to have a life of its own, trying to erode our will. Everyone must hold fast to their principles and not waver in the slightest." Her eyes were resolute, constantly alert to any movement around her.

Lu Zixuan was completely focused on maintaining the "Spirit Void Sacred Array," which constantly changed its form as they moved to deal with any potential dangers. His forehead was covered in fine beads of sweat, and his hands moved incessantly, manipulating the flow of spiritual energy within the array. "The layout of the castle seems to be constantly changing. We must find the core of the dark power as soon as possible, otherwise, if we are trapped, the consequences will be unimaginable."

Bai Youruo played the Spiritual Flute, its notes transforming into tangible golden sound waves that spread through the dark passage. Wherever the sound waves reached, the dark aura dissipated rapidly, like snow meeting the sun, creating a relatively safe passage for everyone. "I can sense that the most powerful dark force is not far ahead. Let's quicken our pace." Her voice was soft, yet filled with determination.

As the group ventured deeper, a massive, dark hall came into view. The hall's doors were tightly shut, covered with complex and malevolent runes that emanated intense dark energy, inspiring awe and fear.

"This should be the entrance to the core of the dark power. Everyone, get ready." Ye Yuanchen took a deep breath and slowly approached the door. He pressed the Spirit Void Holy Sword against the door, attempting to use the power of the sacred artifact to break the runic seal on the door.

Mu Wanyue, Lu Zixuan, and Bai Youruo all channeled their power into Ye Yuanchen, causing a dazzling display of multicolored light before the gate. However, the runic seal on the gate was extremely powerful; their attacks only caused the runes to flicker a few times without causing any substantial damage.

“This seal is much stronger than we expected; a direct assault is not a good strategy.” Lu Zixuan frowned and began to carefully observe the patterns of the runes on the door, trying to find a way to break it.

After some research, Lu Zixuan discovered that these rune seals were related to an ancient dark formation that required a specific spiritual energy frequency to break. "I need some time to adjust our spiritual energy frequency. In the meantime, everyone please protect me."

The group quickly formed a defensive circle around Lu Zixuan. Mu Wanyue wielded her Spirit Whip, repelling the approaching dark creatures. The whip's shadow flickered, creating a dazzling barrier. Ye Yuanchen unleashed the "Spirit Realm Chaos Suppressing God Technique," forming a golden light screen in front of him. Runes flowed across the screen, blocking the invasion of dark power. Bai Youruo played her Spirit Flute, the sound transforming into a sonic shield, further enhancing the stability of the defense. The sound waves rippled through the air, causing the surrounding dark aura to tremble.

Lu Zixuan silently calculated within the defensive perimeter, his hands rapidly changing hand seals to precisely adjust the frequency of everyone's spiritual energy. After a moment, he shouted, "Now! Inject your spiritual energy into the gate at this frequency!"

Following their instructions, everyone channeled their adjusted spiritual energy into the gate. This time, the runic seals on the gate trembled violently, their light flickering erratically. With a deafening roar, the gate slowly opened, and an overwhelmingly powerful dark force rushed out, like a surging black tide, attempting to engulf them.

Ye Yuanchen and the others hurriedly activated their spiritual energy shields to resist the impact of this dark power. When the light dissipated, they saw a massive dark magic crystal floating in the center of the hall. The crystal was entirely black, with black liquid surging within, like an endless source of darkness. Countless dark runes surrounded the crystal, constantly channeling dark power into it, making it ever more powerful.

"This is the core of the dark power. Destroying it will save the Three Realms!" Ye Yuanchen's eyes were firm. He gripped the Spirit Void Holy Sword and charged towards the Dark Magic Crystal first.

However, the instant he approached the magic crystal, a colossal figure of a dark demon god slowly emerged from it. The demon god's form was as imposing as a mountain, its entire body covered in black scales, each scale shimmering with an evil light. Its head resembled a gigantic black tumor, upon which grew countless blood-red eyes, revealing boundless greed and cruelty. The demon god's hands were like two enormous black scythes; with each swing, black cracks were torn through space.

"You lowly ants, how dare you trespass into the territory of this demon god? Do you think you can easily destroy this dark magic crystal? You're delusional!" The dark demon god roared, his voice like rolling thunder, causing the surrounding walls to tremble violently and countless stones to fall down.

Undeterred, Ye Yuanchen and the others quickly formed a battle formation. Ye Yuanchen stood at the forefront, acting as the vanguard. He perfectly fused the power of the Spirit Realm Key and the sacred artifact, infusing it into the Spirit Void Sacred Sword. The Spirit Void Sacred Sword instantly unleashed an unprecedentedly dazzling light, a light containing the power to purify all evil, seemingly capable of dispelling all darkness in the world.

Mu Wanyue stood to Ye Yuanchen's left, wielding the Spirit Whip and raising her spiritual power to its limit. The whip and Ye Yuanchen's spiritual power resonated with each other, forming an unbreakable defensive line. Her movements were agile, her eyes sharp, always ready to deliver a fatal blow to her enemy.

Lu Zixuan had set up an even more powerful "Spirit Void Annihilation Chaos Sacred Array" behind him. This array combined the essence of array formations he had learned throughout his life with the power of sacred artifacts, capable of gathering and amplifying the power of everyone together. Within the array, spiritual energy flickered, like stars about to explode, poised to unleash their power.

Bai Youruo stood at the core of the formation, playing the Lingxu Lingyin Flute. The flute's sound transformed into a powerful soul-purifying force, enveloping the entire battlefield. The sound waves, like invisible blades, directly targeted the Dark Demon God's soul, weakening its soul power and interfering with its thoughts and actions.

"Today is your death day, Dark Demon God!" Ye Yuanchen roared, charging towards the Dark Demon God with the Spirit Void Holy Sword in hand. He unleashed his full power, the Spirit Void Holy Sword slicing through the air with streaks of sharp light, each beam containing enough power to destroy a mountain, aiming for the Dark Demon God's vital points. Wherever the light passed, the dark aura surrounding the Dark Demon God was dispelled, revealing a brief patch of light.

Mu Wanyue followed closely behind, unleashing her strongest immortal technique, "Spiritual Dance Illusionary Whip Void Break." The spirit whip transformed into countless pink rays of light, weaving around the Dark Demon God like agile dragons, lashing at his body and restricting his movements while continuously draining his dark power. The whip's shadow flickered, the pink light contrasting sharply with the Dark Demon God's black body, each lash accompanied by the Dark Demon God's furious roar.

Lu Zixuan manipulated the flow of spiritual energy within the formation, constantly adjusting its attack angle and intensity. Powerful spiritual energy arrows and shockwaves rained down upon the Dark Demon God. The spiritual energy arrows streaked across the darkness like meteors, striking the Dark Demon God's body precisely, leaving deep wounds and splattering black blood.

Bai Youruo's spirit flute playing grew increasingly intense, its notes like invisible blades relentlessly slicing through the Dark Demon God's soul. The Dark Demon God's movements gradually slowed, its attacks became chaotic, and a hint of fear appeared in its eyes. Under the onslaught of the flute's music, the Dark Demon God's soul seemed to be caught in a raging storm, struggling in agony.

"You wretched ants, how can you possess such power!" The Dark Demon God roared furiously, attempting to launch an even more powerful attack to turn the tide. It wielded its enormous scythe, from which black flames erupted, sweeping towards Ye Yuanchen and the others. Wherever the flames touched, space distorted, and the temperature plummeted, as if freezing everything in darkness.

However, Ye Yuanchen and the others' attacks were relentless and unstoppable, giving the Dark Demon God no chance to breathe. Under the combined assault of the group, cracks began to appear on the Dark Demon God's body, and its black aura grew increasingly faint.

"Give it your all, victory is within reach!" Ye Yuanchen shouted, his eyes revealing unwavering faith and determination to win. He further enhanced the power of the Spirit Void Holy Sword, its light shining even brighter, as if illuminating the entire dark hall.

Upon hearing this, the crowd attacked even more frantically. Finally, with a deafening roar, the Dark Demon God's body collapsed, turning into a cloud of black smoke and dissipating into the air. With the Dark Demon God's demise, the Dark Magic Crystal, having lost its protection, began to tremble violently.

Seizing the opportunity, Ye Yuanchen thrust the Spirit Void Holy Sword with all his might into the Dark Demon Crystal. The instant the Spirit Void Holy Sword pierced the crystal, the power of the sacred artifact erupted, surging along the sword and into the interior of the crystal. The Dark Demon Crystal emitted a dazzling light, followed by cracks appearing. The cracks rapidly spread, becoming more numerous and larger.

Finally, with a deafening roar, the Dark Crystal shattered completely, dissipating into countless fragments into the air. As the Dark Crystal shattered, the dark power that had shrouded the Three Realms rapidly dissipated. Sunlight shone upon the earth once more, the land corrupted by darkness gradually regained its vitality, withered spiritual plants shone with renewed green light, the sects and holy sites of the cultivation world began to be rebuilt, the spirit race of the spirit realm rejoiced, and the wars, plagues, and famines of the mortal realm gradually subsided.

Looking at this hard-won peace, Ye Yuanchen and the others were filled with relief and pride. They knew that the hardships and tribulations they had endured along the way had finally come to an end, and that they would become legendary heroes in the history of the Three Realms, forever remembered by future generations.