My Perfect Isekai: Pragmatic Protagonist, Progression Fantasy and Strategy

The fiftieth floor of the Oakhaven dungeon did not welcome intruders with sprawling lava lakes, howling blizzards, or suffocating swamp mist. Instead, the final descent opened into a colossal, circular amphitheater carved entirely from pitch-black, ancient basalt. Its towering, vaulted ceiling stretched high into the darkness, supported by massive monolithic pillars that hummed with centuries of compressed, ancient dungeon mana.

In the center of the vast, silent arena stood the Fiftieth Floor Gatekeeper—a fifteen-meter-tall Obsidian Golem bound in thick, glowing bands of crimson iron. Its central chest core, visible through gaps in the heavy stone plating, pulsated with a dense, deep-purple light that radiated immense gravitational pressure, warping the air around it in visible, translucent ripples.

”Fifty-floor milestone,” I murmured, stepping smoothly onto the polished basalt floor. My black coat remained pristine, untouched by the ash, soot, or blood of the lower biomes. Inside my chest, my sapphire reactor purred with a steady, quiet power, operating smoothly at a calibrated sixty percent throughput. ”A clean benchmark.”

”Radary czyste, szefie!” Kaede’s cheerful ping echoed from my left pauldron in our native Polish operational cipher, her small spider legs tightening securely against my collar. ”Ten kloc ma tarcze z płynnej magmy i osłonę grawitacyjną, ale jego obwód chłodzenia pod łopatkami jest odsłonięty! Jeden czysty strzał w węzeł i po zawodach!”

”Shnee, take the left flank,” I instructed calmly, my sapphire eyes narrowing with calculating focus as I analyzed the golem’s structural alignment. ”Keep its heat output contained. I’m finishing this in a single exchange.”

Shnee smiled with quiet, predatory grace, her Celestial Silver rapier whistling through the air as she blurred into motion like a silver flash. Concentrated, razor-sharp streams of frost mana erupted from her blade, striking the molten joints of the titan’s lower legs. The sudden, violent thermal shock caused the glowing iron bands to crack with deafening, metallic snaps (CRACK!), freezing the molten lubricant in its joints.

The Obsidian Gatekeeper roared—a hollow, thunderous sound like two grinding tectonic plates—and swung a massive, twenty-ton basalt fist directly toward my head. The sheer momentum generated a gale-force shockwave that blasted loose stone and gray dust across the arena.

I didn’t step back. I didn’t even draw a weapon.

With hands loosely tucked into my coat pockets, I accelerated forward in a straight line. As the twenty-ton fist descended, I raised my right arm with calculated, effortless fluidity, coating the entire limb from fingertips to shoulder in the dense, light-absorbing black shell of my Gōtai. The black energy hummed with an absolute, unyielding density, warping the ambient light around my forearm.

BOOM!

The golem’s colossal fist slammed directly into my black-armored palm. The impact shook the entire fifty-floor amphitheater, sending shockwaves rippling through the ancient basalt floor, but my feet remained anchored to the stone like titanium pillars. The shockwave radiated outward, shattering the basalt floor around my boots into fine powder, yet my Gōtai absorbed ninety-nine percent of the kinetic force without a single tremor.

”Is that all?” I asked quietly.

Before the titan could retract its colossal arm, I drove my right palm forward into the golem’s chest plate. I unbuckled a mental valve in my energy pathways, letting a concentrated charge of sapphire current flow straight from my internal furnace through my reinforced channels. My widened mana weaves handled the sudden, monstrous surge without a single tremor or spasm. A triple-voltage impulse of Sapphire Lightning blasted through the two-meter-thick obsidian plating, channeling directly into the pulsating purple core.

BOOM!

The internal pressure of the electrical discharge exceeded the structural tolerance of the golem’s core. The fifteen-meter titan froze mid-stride, its crimson runes flickering violently before exploding from the inside out into a shower of harmless basalt dust, glowing iron filings, and steaming ash.

A massive, pristine purple core—the size of a human head—fell smoothly through the air. I caught it telekinetically with a flick of my wrist and deposited it into my dimensional storage pouch.

Behind the disintegrated boss, the massive archway of the fifty-floor portal ignited with a soft, azure light, linking directly back to the surface sanctuary of Oakhaven.

”To by było na tyle!” Kaede chirped happily, stretching her small spider legs. ”Połowa lochu oficjalnie roztrzasana! A teraz szefie, powrót do Gryfa na konkretne jedzenie, bo mój pancerz ze śluzu spalił milion kalorii na te podmuchy mrozu!”

Taken from NovelPhoenix, this narrative should be reported if found on Amazon.

”Agreed,” Shnee said softly, sheathing her rapier with a crisp, elegant click. ”A proper meal is long overdue.”

An hour later, we stepped out of the dungeon portal chamber and into the warm, late-afternoon sunlight of Oakhaven. The fresh surface air was thick with the scent of roasted pine, damp earth, and distant woodsmoke—a sharp, deeply comforting contrast to the suffocating sulfur, ash, and freezing mists of the lower biomes.

We navigated the bustling cobblestone streets of Oakhaven, making our way toward the familiar silhouette of the Golden Griffin. The late-afternoon sun cast long, golden shadows across the stone facades of the guild houses and merchant stalls. Adventurers, guild guards, and local merchants turned to stare as we passed, their eyes lingering on my pristine black coat, Shnee’s elegant silver rapier, and the calm, effortless composure surrounding our group. Whispers had already spread like wildfire through the guild hall that a three-person party was speedrunning the lower floors of the dungeon with terrifying, unprecedented efficiency.

When I pushed open the heavy oak doors of the Golden Griffin, the warm, familiar tavern atmosphere washed over us. The crackle of the hearth, the clinking of ale tankards, and the rich, savory aroma of simmering broth filled the room.

Mina was wiping down a wooden table near the entrance. The moment her eyes met mine, her rag slipped from her fingers, and a brilliant, genuine smile lit up her face.

”Dave! Shnee! Kaede!” Mina called out, her voice filled with relief. She turned quickly toward the kitchen doors. ”Mother! They’re back!”

Elena emerged from the kitchen seconds later, her hands wiping against her crisp white apron. Her warm, maternal eyes immediately scanned the three of us, evaluating our posture and checking for any hidden signs of fatigue or injury. Her warm, maternal eyes scanned the three of us, checking for any signs of injuries or exhaustion. Seeing our untouched, steady composure, she let out a soft, relieved breath.

”You’re back safe,” Elena said warmly, stepping forward to welcome us. ”Come, sit at your usual corner table. I’ve had a pot of rich pork bone broth simmering for hours, and the roast venison is fresh off the spit.”

”Jadło!” Kaede squeaked happily, scuttling down my arm onto the polished oak table. ”Pani Eleno, potrójna porcja boczku i gorący ramen! Połowa lochu padła, dzisiaj świętujemy!”

Elena laughed warmly, nodding as she headed back into the kitchen. ”Potrójna porcja it is, Kaede.”

We sat down at our favorite corner table by the window. Within minutes, Mina and Elena brought out a feast fit for a royal guild expedition: steaming bowls of rich Tonkotsu ramen topped with tender, seared pork belly, soft-boiled eggs, and fresh green onions; platters of thick, juicy roast venison drizzled with berry reduction; crusty loaves of fresh rye bread; and clay jugs of cold spring water.

I took a slow, deep breath, letting the savory steam expand my chest. The grueling physical toll of maintaining sixty percent reactor output and fighting through fifty floors of hostile biomes was instantly mitigated by the calorie-dense food and the peaceful atmosphere of our sanctuary. My upgraded Vessel absorbed the nutrients smoothly, reinforcing my energy pathways.

As we ate, a quiet knock echoed at the side entrance of the tavern. A tall figure wrapped in a dark velvet cloak stepped inside, pulling back his hood to reveal the sharp, calculating face of Silas, the guild’s premier merchant and underground broker.

Silas bowed respectfully before pulling up a chair at our table. His sharp eyes immediately darted to my dimensional storage pouch.

”I hear rumors from the guild hall that you reached the fiftieth floor today, Dave,” Silas said in a hushed, reverent voice. ”Is it true?”

Without a word, I reached into my pouch and placed a heavy, velvet-lined wooden chest onto the table. I flipped open the brass latches, revealing twenty pristine, glowing purple cores, three ingots of pure liquid silver solidified into dense blocks, and several slabs of rare runic obsidian.

Silas gasped, his hands trembling as he stared at the fortune sitting before him. He pulled a brass magnifying loupe from his vest and examined the pure silver blocks with wide, disbelieving eyes.

”By the gods...” Silas whispered, his voice shaking with awe. ”This quantity... the purity of this silver alone is worth a small baron’s estate! Combined with these purple cores, you have accumulated enough capital to purchase an entire district in Crossgard!”

”That is the goal,” I replied coldly, taking a sip of cold spring water. ”Calculate the total value and deposit eighty percent into our private merchant account. Use the remaining twenty percent to secure discreet transport and purchasing permits for Crossgard.”

”Consider it done!” Silas nodded frantically, carefully closing the chest and holding it against his chest like a newborn child. ”I will have the official credit drafts ready by tomorrow morning.”

Silas paused, his expression shifting from greedy excitement to cautious concern. He leaned in closer, dropping his voice to a barely audible whisper.

”One word of warning, Dave,” Silas murmured. ”Lord Kaelar’s informants have been watching the dungeon entrance. He knows you’re clearing the lower floors at an impossible speed. His personal guard has been mobilizing near the upper noble quarter. He won’t let a party with this much independent power leave Oakhaven without trying to chain you to his house.”

I met Silas’s gaze with cold, unwavering sapphire eyes. Deep within my chest, my sapphire reactor purred with silent, lethal promise.

”Let him try,” I said softly.

Silas shuddered at the icy chill in my voice, bowed quickly, and slipped out through the side door with the treasure chest.

Kaede finished her third piece of seared pork belly, letting out a satisfied, contented sigh. ”Szefie, Silas ma pełne portki ze strachu przed tym Kaelarem, a nie wie, że dla ciebie ten szlachcic to po prostu kolejny kloc do zutylizowania.”

”Step by step,” I said, leaning back against the wooden bench and looking out the window at the setting sun over Oakhaven. ”First, we rest. Tomorrow, we prepare for the final stretch.”

Shnee looked at me, her blue eyes reflecting the warm glow of the tavern hearth, a quiet, unshakeable trust shining in her gaze.

The first fifty floors of the dungeon had fallen. The foundation was built. And whatever Oakhaven or Kaelar threw at us next would simply be crushed under the weight of our relentless progression.