I AM EXTRA IN A SHONEN MANGA

The ruined corridor was quiet, save for the dripping of water seeping from cracked stone. Dust drifted through the shafts of light above, and every step echoed like a whisper of warning.

Khael paused mid-stride, his eyes narrowing. Something scratched against the edge of his perception not sound, but a pulse, faint and unsettling. He crouched, brushing his fingers against the ground.

"...What is this?" he muttered, his voice low.

Ceyla, trailing behind, frowned at the way Khael's hand trembled over the stone. She leaned in, her stormy Shinrei flickering faintly in her eyes. What she saw made her curse aloud.

"What the fuck…"

The floor, the walls even the ceiling were carved with jagged marks. Dozens of them. Not random scratches, but spiraling sigils that seemed to writhe if stared at too long. They pulsed faintly with void energy, like veins feeding into some unseen heart.

Juno's expression hardened, his body instantly on guard. He tapped the hilt of his weapon, scanning their surroundings with sharpened focus.

"These aren't just markings. They're… seals. Or maybe… the remains of one."

Khael traced one of the sigils, his jaw tightening as he felt the faint resonance crawl beneath his skin.

"It's not dead. Whoever put this here — it's still feeding. Gathering."

Ceyla's storm Shinrei flared instinctively, her eyes darting around.

"Gathering what? Don't tell me it's pulling Voidborn through."

The walls seemed to answer her, a low hum vibrating through the air as if something beneath the ruins had been waiting for them to notice.

Juno clenched his fists.

"No. This is worse. These marks… they're a gate. And someone's trying to unseal it."

Khael's gaze lingered on the spiraling marks. His voice was steady, but his eyes betrayed the storm behind them.

"The question is… why? Why would they try to unseal this? What purpose does it serve?"

He swallowed hard, trying to piece together fragments of a story only he knew.

(Think… what the hell happened in the manga? What did they unseal back then…?)

His mind spun. He saw flashes distorted panels burned into his memory. A broken battlefield. A lone figure swaying with blood dripping from his chin.

Raiden, the Eclipse Vanguard.

Khael could almost hear the words again, like they were whispered from the past.

"Don't worry… everything is over."

Raiden's voice, calm yet hollow, as he yawned through the blood.

(Damn it… what exactly did Raiden fight that day?)

The memory sharpened — Kaen's perspective, Kaen's terrified eyes as he looked at Raiden's hand. Not a hand anymore. Something else.

A writhing, segmented tail.

(A worm's… tail?)

Khael's stomach dropped. He clenched his fists, his pulse hammering as the realization struck like ice.

"…Don't tell me…" he whispered under his breath. His face twisted, his voice low and edged with dread.

"…It's a worm-type Voidborn…? Tsk…"

The air around the sigils seemed to thrum in agreement, as if mocking him.

Ceyla caught the look on his face and frowned.

"Oi, Khael. What's wrong? You look like you've seen a ghost."

But Khael forced his expression back to neutral, burying the storm of knowledge clawing at him.

(I can't say it… not yet. Not until I know for sure.)

Khael's eyes hardened as the markings pulsed faintly, Shinrei bleeding from them like a wound in the earth. The pressure in the air was suffocating, whispering of something far worse beneath.

He drew a sharp breath and barked,

"I'm going to close this… Guard me!"

Juno tilted his head, suspicious, but he cracked his knuckles and stepped forward.

"Don't take too long."

Ceyla spun her storm-forged dagger, electricity buzzing in the air.

"If Voidborn crawl out of that thing, I'll fry 'em before they touch you."

Khael nodded, but his chest felt heavy. His hand hovered over the jagged spirals. He could feel it, this wasn't something ordinary Shinrei sealing could mend. His mind sharpened, and the words of an ancient oath stirred in him.

(No choice… This corruption won't yield to normal arts. If I hesitate, it'll spread. But… if I use that…)

His fist trembled. He clenched his jaw.

(They won't know. They can't know. Dragon Knights… they don't exist anymore. As far as this world remembers, they never did. To them, this will just look like another Echo Art…)

He pressed his palm down. His Shinrei ignited—not in the familiar flame of his affinity, but in a deeper, heavier resonance, like the roar of a buried beast. Ancient scales shimmered faintly across his arm, just for a moment, before fading into raw light.

Ceyla blinked, her eyes narrowing.

"…What the hell kind of Shinrei is that?"

Juno frowned but stayed silent, feeling the weight of the energy crawling across his skin.

Khael gritted his teeth and whispered words not spoken aloud in centuries:

"Ars Equester Draconis: Dens Obsignatus."

A circular glyph of interlocked dragon sigils erupted beneath his feet, biting into the earth. The writhing marks across the gate flared violently, shrieking like wounded beasts, before they were dragged inward and crushed beneath the glyph's fangs.

The ground shook. The echo of a roar not human, not beast, but something ancient—rippled across the air before vanishing.

Khael's breath came heavy, sweat trickling down his temple. His palm still burned from the backlash.

(It's done… but if they saw too much… Damn it, I'll have to lie my way through this.)

Ceyla tilted her head, still eyeing him.

"…Khael… what was that?"

Juno crossed his arms.

"That wasn't a normal Vein Gate technique."

Khael forced a smirk, hiding the tightness in his chest.

"Just… an old sealing art I picked up. Don't overthink it."

But deep inside, his thoughts churned.

(If the gates are already being tampered with… and if that was really a worm-type… then Lady Sythen's plans are closer to completion than I thought.)

As the last trace of the mark sizzled away into nothingness, the ground settling into silence.

Khael exhaled sharply, his palm still trembling from the strain. But instead of relief, his gaze darkened. He straightened, eyes sweeping across the corrupted stone.

"It's not over yet…" his voice was steady, but heavy with urgency. "…I need to close all of this."

Juno's brows furrowed.

"All of this? You mean… there are more?"

Ceyla followed Khael's eyes. And only then did she notice it, faint outlines of other marks etched farther along the ground, some hidden in shadow, others faintly glowing as if waiting for their turn to awaken. Her grip on the dagger tightened.

"…Shit. There's a whole network of them."

Khael nodded grimly.

"If even one of these stays open, it'll keep feeding power to the Gate. Sealing one isn't enough."

(This isn't just an unsealing attempt… it's a ritual. They're carving open a path. Tsk… how many did Lady Sythen already plant?)

Ceyla spat to the side.

"Damn it. And here I thought we were done babysitting a cursed rock."

Juno glanced at Khael again, the strange glow of his technique replaying in his mind.

"Then say the word. You guard, we kill."

Khael gave a short nod. His hand closed into a fist, hiding the faint shimmer of scales that still lingered across his knuckles.

"Stay sharp. Until every last one is closed, this fight isn't over."

To be continue