Mark couldn't answer any questions. It was as if he did everything simply because he was able to. But he had made a promise to himself: when his year-and-a-half term in the dungeon ended and a new set of clothes appeared in the safe zone, his preparation would already be complete. If the Hydra was still at Rank A- at that time, he decided he would carry out his plan.
Time passed quickly. Finally, a new set of clothes appeared by his bed. Mark looked at them, lost in thought for a moment, then began to put them on. He was nearly ready for the plan, and the Hydra remained at Rank A-. That meant it had to be today. After changing, Mark headed to the second floor—the Hydra's territory.
On the way, Mark thought about the Hydra's unique anatomy and its weak points. In appearance, the Hydra resembled a six-headed serpent, but internally, it was nothing like a snake. It had no heart, no lungs, and no other vital organs. Its body consisted mostly of a uniform structure, which helped boost its regeneration. If one could say it had any distinct organ at all, it was only the stomach-like pouch where food was collected.
To kill it, one had to either split its body in half horizontally or cut off all six heads. Also, like any other creature, it could be killed by destroying its "Monster Core." Splitting it in two required a single, incredibly powerful strike. Cutting off six heads was a long and extremely difficult process. As for the Monster Core, it was the most vital organ for any monster, and in the Hydra's body, it was exceptionally well-protected.
Mark stood waiting on one of the Hydra's frequent paths. Whether it was from his constant observation of the monster's habits or the persistent vibrations transmitted through his Earth Sense, he knew the monster would arrive soon. Today, in this desolate and abandoned place, either he or the Hydra would perish.
The silence of the dungeon weighed heavily on the air, but Mark had already begun to move. The hesitation that had haunted him all this time finally vanished. Now that the decision was made, there was no more room for doubt—there was only the action that followed.
First, Mark pulled a large monster carcass from his system inventory and slit its belly open with his short sword. The internal organs spilled out, releasing a nauseating stench, but Mark had no time to dwell on the smell. He retrieved a stone, roughly one meter in diameter, from his inventory and began to enchant it. From the outside, the stone appeared unchanged, but anyone with a sense for mana would have felt the volatile energy surging within. Once the enchantment was complete, he shoved the stone deep inside the carcass, securing it so it wouldn't fall out. Stowing his blind staff and short sword back into his inventory, he retreated to hide nearby.
The Hydra was approaching. Mark poured all his mana and focus into maintaining the spell on the distant stone—a task that grew more exhausting with every passing second. Finally, the Hydra arrived and, without hesitation, swallowed the carcass whole. The moment Mark felt the bait settle into the Hydra's stomach-like main pouch, he let out a sharp breath and released the spell.
A muffled explosion thundered from within the monster. Internal ruptures tore through the Hydra, and it let out an agonizing scream from all six heads, a sound that threatened to shatter one's eardrums. Mark immediately burst from his hiding spot, moving at a speed that blurred the vision. To an observer, it would have seemed as though his feet weren't touching the ground, as if he were stepping on the air itself.
Despite having six heads and technically six brains, the Hydra usually acted with primitive stupidity. However, under the shock of the attack, it began to use its intellect to search for the culprit. It spotted the tiny figure closing in. Concentrating its rage, the Hydra spat a highly pressurized stream of acid from all six heads directly at Mark. Mark, now 20 meters away, judged the distance sufficient. Suddenly, as if something had detonated beneath him, he was propelled into the sky. The blast sent him upward and toward the monster, but one explosion wasn't enough to reach his target. In mid-air, he triggered another mana-burst, forcing his body even higher.
Now, Mark was directly above the Hydra, nearly 60 meters in the air. Gravity began to pull him back down. The Hydra realized the "tiny thing" had vanished only to reappear above it. Enraged, it tilted all six heads straight up and began spraying acid once more, aimed at the falling shadow.
As Mark hovered in the air and began his descent, he could sense all six heads fixed on him, a massive amount of liquid acid spraying in his direction. He extended his right hand downward. Suddenly, a vast mixture of various-sized stones and sand materialized in the open space between Mark and the Hydra. The mass absorbed the acid strike completely and, carried by inertia, began to fall directly toward the Hydra.
A deluge of earth and stone rained down upon the beast. But that wasn't all. Mark infused his mana entirely into the mixture, seizing control with HEEM (High Earth Element Manipulation). The mixture began to move as if it were alive, coiling around the Hydra and attempting to seal its maws. Whenever the Hydra tried to open any of its six mouths, Mark immediately filled them with suffocating earth. At the same time, large quantities of sand began to pour into the wound in the creature's belly, used to widen the tear and inflict internal damage. Finally, Mark landed directly on top of the Hydra—or rather, on the thick layer of sand that had encased and immobilized it. The Hydra was now completely paralyzed, trapped within its tomb of earth and stone.
Mark had no time to spare. The Hydra was struggling, its muscles twisting with a violence that suggested it could break free at any moment. Worse still, its acidic bodily fluids were so potent they were beginning to dissolve the very stone and sand Mark was using to bind it. Every passing second was a gamble with his life.
Without hesitation, he rushed toward the gaping wound in the creature's belly. Using HEEM , he forced the jagged opening wider, maintaining a temporary stone tunnel to allow him passage into the beast's interior.
Mark stepped inside the Hydra. The air was thick with the suffocating stench of decay and high-concentration acid; the protective sand he had sent in earlier was eroding at a terrifying rate. He pushed deeper until he reached the section housing the Monster Core. The flesh surrounding the core was exceptionally dense and resilient, a biological armor that HEEM alone could not breach.
Understanding the gravity of the situation, Mark retrieved his Blind Staff from his inventory. He prepared his most devastating piercing spell: Big Stone Bullet 2.0. Mark took aim at the Monster Core—a football-sized target buried under half a meter of dense, reinforced muscle. Leaving only a tiny shred of mana for himself, he channeled every other drop into the spell for a single, final, and maximal strike. The air surrounding the staff hummed and vibrated with the sheer density of the mana being compressed into the stone projectile.
The spell was a success. The human-fist-sized stone bullet tore through the dense muscle and struck the Monster Core directly. Mark couldn't confirm the core's utter destruction; he had no mana left to spare, not even for a simple "mana sense." He could feel the Hydra thrashing violently and the stone tunnel he had built inside it collapsing. Using his last bit of mana, Mark propelled himself out through the Hydra's wound using the energy of an explosion. He shot out of the monster like a projectile and crashed to the ground a few meters away.
After rolling several times, Mark finally came to a stop. With this last movement, he was completely exhausted—his body refused to move, and his mana pool was entirely depleted. He lay ten meters away from the monster, listening to the agonizing screams of all six heads as the beast thrashed in its death throes, striking blindly in every direction.