As I stepped into the black mouth of teleportation, I found myself transported to a vast, dimly lit place known as the Refinement Station. The 605 system explained me with a robotic voice:

[Participant 137, this new zone will be a great help for cultivating your strength. It is worth adding that this place is completely safe.]

Taking a deep breath of the cool air, I felt an unfamiliar scent entering my nostrils, leaving a pungent taste on my tongue. I wanted to spit to get rid of the unpleasant sensation, but as I looked down, I noticed a complex network of thin electrical threads spreading out under my feet. They were sparkling like diamonds but emitted repulsive sounds when sparks of the color of the sky exploded around me. As I was about to lift my leg, another spark ran under me, and I heard the sounds of footsteps nearby.

I raised my head and looked around, only to find myself enclosed by the same metal walls, which seemed to stretch endlessly in every direction. Breathing heavily, I leaned my back against the wall and tried to calm my nerves.

On both sides of me, there were lengthy and straight passageways with gleaming metal walls that shone with a chilly radiance and reflected the blue light. Nevertheless, the electric discharges, which I detested, had begun to cloud my vision.

A sudden sensation of warmth spread throughout my body as I stood motionless. It was a unique feeling of comfort and security that I had never experienced before. The warmth was so powerful that I could feel it even in the soles of my feet, bringing a strange sense of relief to my soul. It was as if the electric discharges were not just obstacles, but also a potential source of power that could be harnessed to enhance my strength.

As I stood there, trying to make sense of the energy that surrounded me, I turned to the 605 system for answers. However, much to my surprise, the system refuted my initial assumptions.

In the end, the system provided a wealth of knowledge about the Arena.

[The Arena is a testament to the incredible power and strategic minds of the demons who created it. It is a completely self-sufficient environment, designed to function like an eternal terrarium, where the creatures within can thrive and evolve without any external interference.

Each of the seven levels and 36 floors of the Arena has been meticulously crafted with artful artifacts that serve a vital function in sustaining the ecosystem within. The air itself is purified by these artifacts, and the walls and floors are infused with pulsating veins that resemble human veins, which provide nourishment to the artifacts.

The demons who created the Arena were the most brilliant strategists of their time. But... Despite their incredible power and strategic foresight, the demons eventually fell in the Great Battle and were completely wiped out by humans for centuries. Their once-mighty territories were absorbed by the Empire, and their legacy, which could have raised formidable demonic generals, is now reduced to a place where the weakest creatures fight to the death in the Arena. The sad irony is that the Arena, created by demons who were once the greatest fighters in the land, are now reduced to being a mere source of entertainment for lesser beings.]

As I absorbed the incredible information provided by the system, I sensed a tinge of sadness in its robotic voice.

Just as I was about to inquire further, a figure materialized to my right. It was a frail creature draped in a voluminous black robe.

"Fighter number 25,609, follow me, your Healing Reservoir is ready to use," it stated in a voice barely above a whisper.

Clutching my injured shoulder, I furrowed my brow in confusion. The creature offered no further explanation and turned away, inviting me to follow with a subtle movement of its hooded head.

[Participant 137, you should hurry. Otherwise, you may be blocked here until the end.] The system warned.

I swallowed hard and nodded, my senses assaulted by the strange and pungent odor emanating from the hooded figure. I tried to catch up with the diminutive guide, but no matter how much I quickened my pace, I couldn't keep up.

Abandoning my attempts to study the creature more closely, I gazed around at my surroundings. The metal walls stretched on endlessly, but their once-glaring shine had dulled to a more tolerable level for my light-sensitive eyes.

The buzzing sound grew louder and more intense as we ventured deeper into the unknown place. The dim gray light began to shift, transforming into a sickly green hue, and the stench became unbearable. The walls around us became adorned with protruding symbols etched in some kind of dark substance.

Eventually, the creature stopped and raised a hand, muttering something hoarsely. A green glow emanated from his paw-like appendage, coalescing into a magic circle in an instant. The wall in front of us shook and slid noisily aside, revealing an incredible sight.

The vast chamber was primarily filled with capsules containing a greenish liquid, within which dimly visible creatures floated.

Unauthorized duplication: this tale has been taken without consent. Report sightings.

Without a word, the guide entered the room.

I attempted to ask a question, but the pungent odor overwhelmed me and caused me to recoil.

Despite this, I followed the creature inside the room, my eyes widening in wonder at the sight before me. In addition to the fighters enclosed in the glass capsules, I could see other creatures that resembled my guide, scurrying about from one capsule to another, carrying Spiritual Stones and vessels filled with turbid liquid that were half their size. The entire scene was both fascinating and repulsive at the same time.

I trailed the guide through a labyrinthine maze of angular pathways, lined with nothing but glass capsules and iron wires that crisscrossed the entire floor. As I gazed up at one of the capsules, attempting to discern its contents, a naked creature submerged in a murky liquid suddenly opened its eyes and flashed me a malevolent grin.

Stunned, I froze in place as a jolt of electricity surged through the creature's body, blinding me with its intense glow. I averted my gaze and realized that I had lost sight of my guide. But in the next instant, the hooded figure reappeared, holding out a hand to me.

"Fighter number 25,609, your reservoir is prepared. Please take my hand," he spoke in a raspy voice.

I hesitated before declining the offer, "Just lead the way. I won't be distracted anymore." I observed the pale grey hand disappear into the folds of his black robe.

This time, I kept my eyes fixed on the guide's small, dark silhouette, surrounded by a halo of green light, avoiding any further distractions.

Turning once again, the guide froze and swung his whole body, pointing at something ahead of him.

Rounding the corner, I saw a circular platform with strange symbols etched into its surface.

"Please step onto the platform and hold your breath for as long as possible," the guide rasped from under his hood. Without a word, I let out all the air in my lungs and stepped onto the warm, wire-free surface.

As I stood there, the guide spoke again. "You have won three battles with fatal outcomes for your opponents. Your winnings are 6 Spiritual Stones. You will remain inside this capsule until your scheduled fight with the Boss of the Second Floor. If you need anything, please feel free to call me. Payment, as always, with Spiritual Stones."

I nodded my understanding, and the guide raised a hand. A wall of transparent glass grew in front of me, separating me from the rest of the room. I reached out to touch the glass, but the guide shook his head, and I withdrew my hand.

As the water began to fill the capsule, I panicked and tried to speak, but only bubbles escaped my lips. Suddenly, an electric shock coursed through my body, and I screamed. In that moment, the hood fell back from the guide's head, revealing a mutilated skull with empty eye sockets staring back at me.

Feeling the cold water fill my lungs, I couldn't help but keep my eyes locked on the hooded guide's face. His mouth opened and closed, revealing rows of small, triangular teeth, and I couldn't help but wonder what kind of spell he was casting.

Despite the discomfort, I couldn't look away from the mesmerizing sight of his empty eye sockets. Suddenly, a burning pain shot through my throat, causing me to gasp for water.

I vaguely remembered the small silhouette pulling out Spiritual Stones and placing them next to my capsule.

The grip around my throat tightened, and I grew weaker by the second as the pain intensified.

Finally, I couldn't resist the overpowering feeling any longer and closed my eyes, succumbing to the numbing hum of the water.

As the electric discharges ebbed, I gradually began to feel a healing energy coursing through my body, rejuvenating my skin and strengthening my claws. Two days passed in the blink of an eye, and soon I was checking my stats as I emerged from the capsule.

[Name: Participant 137.

Race: Humanoid.

Grade: 4.

Strength: 115 (+25).

Dexterity: 230 (+20).

Endurance: 90 (+3).

Magic Resistance: 60 (+10).

Luck: 2.

Experience points: 150.

Mana Perception: 17 (+5).

Intelligence: 12 (+15).

Mental Strength: 17 (+15).

Regeneration: 80 (+25).

Skills:

Melee (initial-red), Exoskeleton Cultivation (initial-red), Iron Stomach (initial-yellow), Bone Arrows (initial-red). Dark Threads of the Abyss (initial-red).]

After the battles on the Second floor, my experience points had increased to exactly 150. Additionally, with the remaining Spiritual Stones from the Survival Crossroads, I was able to level up my Melee and Skeleton Cultivation skills.

The black-robed guide was the last thing I saw before teleporting to the battlefield.

As I arrived, I was greeted by a blinding flash of light that left me momentarily blinded. Blinking my eyes repeatedly, I tried to adapt to the intense brightness while catching the announcer's voice.

"Ladies and gentlemen, please welcome our next challenger. Will water sharpened stone and the sun absorbed water be able to defeat iron today? Achias, who will be facing off against the infamous Iron Sentinel, the Boss of the Second Floor!"

My eyes focused on the massive armored figure at the other end of the arena. Two sharp horns protruded from the top of his helmet, adding to his intimidating appearance.

The deafening applause signaled the beginning of the fight, and I crouched down, ready to strike.

As I prepared to jump, I felt a tremor under my feet, signaling the Boss's approach. His movements were both tense and comical as he slowly lumbered towards me. I almost laughed as I dodged his attack at the last moment, jumping on his back. However, my amusement quickly turned to concern as the Boss broke through the bars at the other end of the field, sending metal fragments and bars raining down on the audience.

I swallowed hard, almost losing my balance as the Boss kicked off with his front paws, standing on his hind legs to dislodge me. Struggling to keep my balance, I dug my claws into the armor, seeking a weak point. But there was none to be found - the Iron Sentinel was virtually invincible, with impenetrable armor and horns of indestructible material.

The Iron Sentinel's movements were slow and lumbering, but his strength was immense.

As hard as I tried, I couldn't so much as scratch the beast, let alone defeat it.

I decided to change my strategy and circled around the boss, looking for a weak spot. Suddenly, the ground beneath me shook, and I stumbled to the side to avoid being knocked down.