Thunder Dragon's Single Flash

The dedicated elevator plunged endlessly into the pitch-black underground depths of the Hunter Association headquarters basement, finally opening with a heavy bursting sound.

Elena, the Alliance ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠Leader, and Gyu-yeon stepped cautiously into the silver underground bunker, wrapped layer upon layer in dozens of special magic barriers like a spider's web.

The moment they entered, a chilling, artificial air pierced their lungs and clung to their skin. The atmosphere was already beyond murderous—it was frozen solid.

Looking around, a jaw-dropping sight unfolded. The massive bunker's walls and impossibly high ceiling were armed to the teeth with rare mana-absorbing minerals that forcibly suppressed and drained hunters' mana. It was the perfect isolation zone: even a nuclear bomb couldn't let a speck of dust or a single vibration escape to the outside.

And at the center of that enormous bunker floor stood a massive special alloy block, used for measuring hunter mana output and experiments, rising like a tombstone.

Elena strode ahead with the clack of her combat boots, lowering her coldly sunken red eyes as she spoke to me.

"That structure is made of high-purity Oriharcon. Even a Sword Master's disciple would struggle to scratch it. So give it your all."

Her voice seemed calm and serene as a lake on the surface, but beneath lurked a sharp blade of suspicion. It reeked of blatant distrust: [The lunatic who vaporized the Tower's dimensional barrier with that insane explosion—isn't you pretending to be fragile, right?]

Elena planned to analyze the energy waves bursting from me at full power, checking if they matched the properties of that cataclysmic explosion.

But she was making a fatal miscalculation.

'Finally, a place where I can cut loose without worrying about wrecking the house!'

I feigned intense tension on the outside, but inside, I was grinning ear to ear, happily pondering which technique to mimic.

The reason Gyu-yeon loved this so much? She'd piled up techniques she wanted to try like a mountain, but could never unleash them freely at home for fear of collapse. A slight miscontrol, and expensive furniture would shatter.

So Gyu-yeon had always stuck to fine-tuned ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠Void Grasping for remotes, cola, or snacks.

But this place? Walls. Ceiling. Even that stern red-eyed Association President glaring at me—everything was tough as nails. Whatever I smashed, however I smashed it, national budget would cover it. The perfect stage.

"Gyu-yeon."

Then, the Alliance Leader behind me called out, staring right at me. He alone knew my delicate girl exterior hid the Sword Master who'd severed the Heavenly Demon's neck.

Sensing my sky-high excitement, the Alliance Leader floated a desperate Hyeon-gwang Heart Language plea that Elena couldn't hear.

To his heartfelt plea laced with urgency, I turned innocently and flashed a bright smile.

My sudden sunny grin made Elena frown, arms crossed as she stared down at me impassively.

I took a careful breath, slowly approaching the massive alloy block.

I didn't draw the Mugyeok Divine Sword. Pulling that blade would turn the test into a farce, literally slicing the Association HQ into "Association" and "Headquarters."

Instead, I lightly picked up a test sword from the bunker's side.

Wooong-!! Ignoring the Mugyeok Divine Sword vibrating furiously like a wife catching her husband cheating, I secured the test sword firmly at my left waist.

'Perfect, setup complete!'

Gyu-yeon lowered into stance, bending her knees to store explosive power in her legs. She inhaled deeply into her lungs.

It wasn't mere breathing. What her lungs absorbed was the breath of wind, the qi flowing through the void itself.

With one breath, nature's energy seeped in, blurring the line between human and world. The profound mystery of perfect unity with nature through a single breath.

Circulating the inhaled qi through her body to convert it into thunder qi, I slowly closed my eyes.

Pajijik-! In that instant, real lightning crackled between breaths, making the bunker's air tremble coldly.

My eyes snapped open, gaze flashing like lightning. The moment the test sword burst from its sheath—

Kwarung-!!!

A cool line etched across the massive Oriharcon block. Then, a belated pachijik-! thunderclap tore the air, slamming everyone's eardrums.

And moments later—

Jjeeng-!!!

The test sword's blade cracked under pressure, silver fissures spreading like lightning. It was about to shatter.

Wooong-! The Mugyeok Divine Sword vibrated cheerily, as if mocking, 'That's what you get for using cheap scrap metal.'

But the researchers in the observation room beyond the glass gaped, speechless.

Even Elena's red pupils, always ice-cold, shook like an earthquake.

I hadn't shed a drop of sweat, but I pretended exhaustion, trembling my right fingers as I inwardly cheered.

'Puhuh-! What a hit! Totally refreshing!'

Behind me, the anxiously watching Alliance Leader finally exhaled in relief, like pulling a bad tooth.

Elena slowly approached the alloy block, staring intently. It wasn't shattered by some massive force—it was sliced. Perfectly, razor-sharp.

A pure strike condensed solely from the will to cut.

"No traces of mana explosion."

She murmured low, gloved finger tracing the clean edge. Her brilliant mind rapidly drew a logical conclusion.

"Pure inner force and thunder qi condensation. This isn't the indiscriminate destruction of explosive energy... It's ultraprecise iaijutsu targeting a single point. Completely different in nature from the brute residual energy that wrecked the Tower's outer wall."

Elena finally withdrew her sharp red gaze, her eyes toward me softening considerably.

"Fine, I admit it cleanly. At least you're not the lunatic behind that Tower wall collapse. No one who sets off bombs wields a sword this refined."

I seized the moment, pitifully half-lowering my clear blue eyes. Shaking my empty left sleeve pathetically, I launched into aggrieved acting.

"H-hic... I didn't do it, really... So unfairrr..."

Outwardly sniffling like chicken-tear sobs, but inside, victory fanfare blared.

'Yes! Nailed it! Suspicion totally dodged!'

Elena snapped her data panel shut with a clack, letting out a long, heavy sigh.

"At such a young age... with that critical physical defect... wielding iaijutsu like that. ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠Worthy of being called the Sword Master's heir."

Elena slightly bowed her head, politely apologizing to me.

"I apologize for my hasty suspicion."

"Hmph, got it."

I pouted my lips, pretending a bit miffed as I accepted.

The Alliance Leader nodded, tension easing as he approached. He patted my shoulder, then floated a grumpy Hyeon-gwang Heart Language.

I brushed off the old man's grumbling and tilted my head up at Elena.

"So, can I go home now?"

Elena stared down at me for a long moment. At last, her rigidly crossed arms loosened. A faint but definite smile touched her icy lips.

"Very well. Your innocence is proven; no reason to hold you. But if you trespass the Tower's upper floors without permission again, or waste that dangerous talent on risky internet streams..."

"I won't! Never! I swear, streams will be peaceful NEET snacks from my room corner only!"

My instant reply and ironclad oath left Elena chuckling in disbelief as she turned away. Her combat boots echoed crisply through the bunker.

"Do as you like. Your Tower access ban stays in the Association system for now... but you're free to go. Alliance Leader, please take the child safely."

The moment her final permission dropped, I hid behind the Alliance Leader, secretly flashing a triumphant V-sign with a beaming smile.

Leaving the heavy air of the Association's deepest level behind, it was a successful return home.