The silence that followed the disarming of the General was heavy and tense, broken only by the hiss of the dying fire that still emanated from the battle axe lying on the volcanic rock floor. The colossal creature, kneeling upon the cracked marble floor of the arena, attempted to raise its left arm to repel our vanguard, but the paralysis caused by the energy discharge from my runic sword locked its muscular circuits. The reddish core in its chest glowed erratically and uncontrollably, emitting faint pulses of light that lost their intensity with every passing second.
"He is trying to channel the remainder of his magical reserves into a residual explosion!" warned Liriel's assistant, pointing the arcane reading device toward the creature's chest with a steady hand. "The internal flow is unstable! If the core collapses without being directed, the impact wave will cover a radius of twenty meters!"
"We will not give him time for that reaction!" I ordered, advancing with a quick stride and aligning my combat stance beside Scarlet. "Lyannis, Scarlet, simultaneous containment strike at the base of the neck! Elara, lock the circulation of the core!"
"Understood!" Lyannis and Scarlet replied in absolute synchronization.
Lyannis advanced from the right, raising her heavy battle axe with both hands and delivering a devastating downward blow with all the strength of her body. The tempered steel blade struck the exposed joint between the shoulder protection and the General's armor collar with millimetric precision, splitting the metal plate and severing the creature's primary mana conduction channels.
In the same fraction of a second, Scarlet executed a deep thrust with her longsword from the left side, piercing the demon's throat and passing through the armor from side to side. At the same time, an energized arrow from Elara cut through the air and embedded itself precisely in the center of the reddish sphere in the chest, sealing the energy channeling with a contained explosion of purifying light.
The General released a deep and muffled sigh, and the ember-like glow of its eyes beneath the horned helmet went out permanently. The colossal four-meter-tall figure trembled for a brief moment and collapsed forward, crashing loudly against the steps of the throne platform. Within a few seconds, the creature's body mass and its heavy dark metal armor began dissolving into a dense mist of arcane dust, which slowly dispersed through the chamber's heated air.
"Threat successfully neutralized!" Scarlet announced, retrieving her longsword and wiping the steel with a dry leather cloth before sheathing it with a satisfying click. "No injuries in any of our ranks."
"The perimeter of the central chamber is completely secure," Lyannis confirmed, resting the handle of her axe against the ground and taking a deep breath to normalize her pulmonary rhythm. "The hostile energy in the environment is dropping drastically."
"Excellent work from everyone," I praised, releasing my combat stance and sheathing my runic sword. "Your coordination during the final phase was simply impeccable."
When the General's cloud of arcane dust finally finished dispersing over the steps of the basalt throne, a singular object remained resting upon the cold stone where the monster's body had collapsed. It was not an ordinary piece of equipment or a common elemental crystal fragment, but rather a flat piece of polished black marble, shaped like a perfect diamond. Deep runic inscriptions were carved into its surface, glowing with a constant and mysterious silver light and emitting a mana frequency completely different from that of any artifact we had encountered up to that point during our ascent.
I approached the platform and carefully picked up the artifact, feeling the gentle, cold vibration emanating from the black stone.
"What is that, Takumi?" Rai'kanna asked, approaching lightly at my side, accompanied by Elara and Vespera, as she looked curiously at the glowing stone.
"It doesn't appear to be an ordinary boss energy crystal," Elara observed, tilting her head to examine the details of the runic inscriptions. "The texture of the material is identical to that of the marble floor in the halls of this twentieth floor, but the enchantment pattern is extremely dense."
Liriel and her assistant approached the center of the platform to conduct a detailed analysis. The assistant knelt beside me and took an arcane magnifying lens from her supply bag, adjusting the aperture of the device to examine the microstructure of the stone's silver carvings.
"This runic language belongs to the engineering system of the tower's own structure," Liriel's assistant explained, running her gloved fingers over the contours of the stone with visible scientific enthusiasm. "It is not a personal-use item or a combat artifact. The equations engraved here function as a locking resonance frequency."
"A passage-release key," Liriel concluded, deciphering the pattern with her natural magical sensitivity. "This runic stone was created to be inserted into a specific mechanism on this floor. The General was not merely the guardian of the chamber, but also the bearer of the device that unlocks the continuation of our route toward the upper levels."
"An unknown runic key..." Vespera murmured, crossing her arms as she observed the artifact's silver glow. "Does that mean the twentieth floor has a physical or arcane lock preventing us from proceeding to the twenty-first level even after defeating the guardian?"
While holding the black marble stone in my hands and listening to the team's deductions, I allowed a calm and reflective thought to organize my assessment of the situation. The architecture of the Demon King's tower is increasingly revealing itself to be a work of systematic and ruthless engineering. As we ascend the floors, the structure abandons simple tests of brute strength and instead demands from explorers a constant capacity for reasoning, observation, and interpretation of the environment. Encountering an obstacle that cannot be overcome merely by the blade of a sword is a valuable reminder that wisdom is just as vital as offensive power. Having the key in hand is only the first half of the equation; the second half consists of patiently mapping the chamber to locate the exact insertion point before taking the next step in our ascent.
"Your deduction is absolutely correct," I declared, rising from the throne platform and showing the runic stone to the entire group. "The fact that the General dropped this artifact confirms that the passage to the twenty-first floor is not simply an open gate. There is a receiving mechanism in this dome or in the adjacent corridors."
"We need to conduct a thorough sweep of all the walls of the central chamber and the pillars of the main hall," Scarlet suggested, looking toward the perimeter of the arena. "The slot for this runic stone must be hidden somewhere in a supporting structure or at the base of the throne platform itself."
"Elara and Rai'kanna, check the northern sector and the side walls of the dome," I ordered, dividing the tasks to optimize our time. "Lyannis and Scarlet, inspect the columns near the entrance. Liriel, Vespera, and the assistant, come with me so we can examine the structure of the basalt throne and the grooves in the raised floor."
"Understood!" they all replied with readiness and discipline, immediately separating into pairs to begin the methodical search throughout the hall.
With the General's threat completely eliminated and the valuable runic stone safely secured, our squad began a detailed sweep of the central chamber, focused on uncovering the secret of the mechanism that would open the doors to the continuation of our advance through the tower.