The group slowly descended the stairs of the underground entrance. The surroundings grew increasingly dark, with only the faint glow of their magical artifacts barely illuminating the path beneath their feet. A damp, decaying smell permeated the air, as if no living thing had set foot here for a long time. The stairs were steep and narrow, and the group could only proceed cautiously, one by one. In the silent environment, only the soft sound of their footsteps echoed within the passage.

After descending for a while, the passage suddenly opened up, revealing a huge underground cave. Stalactites of bizarre shapes hung from the cave ceiling, some like sharp cones, others like cascading icicles, casting mottled and eerie shadows in the dim light. Around the cave were some ancient stone coffins, their lids covered with mysterious runes that shimmered faintly, as if telling stories of bygone eras.

Just as the group was preparing to explore deeper into the cave, suddenly, a series of low, hissing roars came from the stone coffin. Then, the coffin lid slowly opened, and one by one, skeleton warriors, their bodies radiating an eerie glow, crawled out. These skeleton warriors wielded bone swords, their movements agile and undiminished by the ravages of time. They let out sharp cries and charged towards the group.

The members of the Linghe Chamber of Commerce reacted swiftly. Under Lin Yang's command, some quickly set up a defensive array, and a crystalline spiritual energy barrier instantly rose, protecting everyone within it. Others threw out specially made pills, which exploded in the air, releasing dazzling light in an attempt to disrupt the skeleton warriors' movements.

The sword cultivators of the Spirit Sword Sect were not to be outdone. They rode on flying swords, forming a sword formation in the air. The sword cultivators shouted in unison, and the sword formation shone brightly, sending streaks of sword energy shooting towards the skeleton warriors like meteors. Wherever the sword energy struck, the skeleton warriors' bones were shattered. However, these skeleton warriors seemed tireless, charging forward wave after wave.

The disciples of Wanbaoge manipulated various magical artifacts, attempting to find the skeleton warriors' weaknesses. One disciple conjured a small Bagua disc, which spun and emitted beams of colored light, scanning the skeleton warriors. Suddenly, he discovered that the skeleton warriors' spines seemed to be a critical part; if damaged, their movements would be severely restricted.

"Attack their spines!" the disciple shouted. Hearing this, everyone immediately adjusted their attack direction. Members of the Linghe Merchant Guild used spiritual energy rays emitted from their magical artifacts to precisely target the skeleton warriors' spines, while the sword cultivators of the Lingjian Sect unleashed sharp sword energy at their targets. Under the combined attack, the skeleton warriors' offensive was gradually contained, and their numbers dwindled.

However, just when everyone thought they were about to defeat the skeleton warriors, a deafening roar echoed from the depths of the cave. A gigantic skeleton king slowly emerged, twice the height of an ordinary skeleton warrior, wielding a massive bone axe whose blade gleamed with a sinister light. The skeleton king exuded a powerful aura, causing everyone to feel an invisible pressure.

The Skeleton King swung his bone axe, unleashing a black axe beam towards the group. Lin Yang swiftly cast a spatial spell, distorting the surrounding space in an attempt to alter the axe beam's trajectory. However, the axe beam's power was too great; although its trajectory shifted slightly, it still struck the defensive array. The defensive array flickered violently, teetering on the verge of collapse.

"Everyone, stay calm! Don't panic!" Lin Yang shouted. He knew that they had to remain calm, or they would be in dire straits. The alchemists from the Linghe Chamber of Commerce quickly distributed pills to restore spiritual energy, allowing everyone to replenish their strength and maintain their defenses.

An elder from the Spirit Sword Sect stepped forward, his expression grave. "Manager Lin," he said, "this Skeleton King is incredibly powerful; we must go all out. I will lead the sword cultivators to unleash our strongest sword formation to try and restrain its movements. You all should take this opportunity to find its weaknesses." Lin Yang nodded in agreement.

At the command of the Spirit Sword Sect elder, the sword cultivators swiftly changed their sword formation, forming the powerful "Tai Chi Yin Yang Sword Formation." Within the formation, the Yin and Yang energies intertwined, creating a massive vortex of spiritual energy that trapped the Skeleton King within. The Skeleton King struggled fiercely, but could not break free from the sword formation's restraints.

Zhao Wanbao, the head of Wanbaoge, led his disciples in manipulating magical artifacts to attack the Skeleton King. They unleashed various magical treasures, such as lightning pearls radiating lightning and flame crystals capable of releasing flames, hurling them at the Skeleton King. For a moment, the cave was filled with flashes of light and continuous explosions.

Lin Yang carefully observed the Skeleton King's movements. He noticed that each time the Skeleton King exerted force to break free of the sword formation, the spiritual energy fluctuations at its leg joints would become abnormal. He immediately informed the others of this discovery: "Attack its leg joints! That's its weak point!"

Upon hearing this, everyone focused their attacks on the Skeleton King's legs. Members of the Spirit Harmony Merchant Guild manipulated their magical artifacts, unleashing beams of powerful energy that struck the Skeleton King's leg joints. Meanwhile, the sword cultivators of the Spirit Sword Sect unleashed their fierce sword techniques, their sword energy slashing like sharp blades towards the joints.

Under the relentless onslaught, cracks began to appear in the Skeleton King's leg joints. Sensing the threat, the Skeleton King roared madly, attempting to break free from the sword formation's restraints. However, the sword cultivators of the Spirit Sword Sect gritted their teeth, maintaining the sword formation with all their might. Finally, with everyone's combined efforts, the Skeleton King's legs gave way, and it collapsed to its knees.

The moment the Skeleton King knelt, Lin Yang seized the opportunity and unleashed his strongest sword technique, fused with the power of the mysterious light. A dazzling light flashed, and the Skeleton King's head was severed, its body turning into a pile of broken bones.

After defeating the Skeleton King, the group rested briefly before continuing their exploration of the cave. At the end of the cave, they discovered a massive stone door, covered with intricate patterns and inscriptions. The patterns seemed to tell an ancient story, while the inscriptions resembled a long-lost language.

A member of the Linghe Chamber of Commerce, who was well-versed in ancient texts, stepped forward and carefully examined the inscriptions on the stone gate. After a difficult deciphering process, he slowly said, "These inscriptions record that by passing through this stone gate, one can find the mysterious treasure, but at the same time, one will face a final test. This test concerns the recognition of the treasure; if one fails to pass, one will suffer great danger."

Lin Yang looked at the stone gate, understanding that they had come this far, with no turning back. He took a deep breath and said to everyone, "Everyone, we've come a long way, enduring countless hardships. We cannot back down at this final juncture. Whatever trials lie ahead, we must face them together." Everyone nodded, their eyes filled with determination.

So, Lin Yang led the group and slowly pushed open the mysterious stone door. Behind the door was a dazzling light, which seemed to conceal endless secrets and dangers. With trepidation, the group stepped into the light, where they would face the most severe test in the ruins and potentially find mysterious treasures.