Transmigrating as an Extra, But the Heroine Has Regressed?!

"Phew... we got away from those beasts," someone behind him sighed in relief, his voice slightly shaking.

"Yeah, we were lucky. There were hundreds of them," another added, still catching their breath.

"It's a miracle we made it."

"But we're not safe yet," Jin said without turning. "We still don't know what's waiting for us in these ruins."

"Right… Is this the puzzle quest zone you mentioned?" asked one of the students, trying to stay hopeful.

Jin gave a small nod. "That's the theory. According to what professor Slyvia said, some areas have puzzle trials and magical mechanisms—tests that require more than just brute strength."

Broken stone pillars lined both sides of the corridor, their shadows stretching across the ground like ghostly fingers.

The deeper they ventured into the arena, the quieter everything became. The noise of the forest faded behind them and it was so silent.

It was unsettling.

Jin's hands tightened around the hilts of his swords. His thoughts raced with every step.

(Traps could be hidden anywhere… floor tiles, broken statues, even the air.)

He stopped suddenly and raised one hand, signaling his team to halt.

Behind him were six students.

Each of them was breathing hard, still recovering from the chase outside. But they trusted Jin.

Despite his sharp tongue and overreactive nature, he had a sharp mind and quick instincts.

"Step only where I step," Jin warned them, narrowing his eyes as he studied the old tiles ahead.

"Some of the tiles are marked differently. The trap might be pressure-based."

The team nodded silently and began moving slowly behind him, mirroring his every move.

They didn't know what lay ahead in the ruins—but if there was anyone who could guide them through it, it was Jin.

"Maintain the V-formation," Jin commanded firmly, eyes locked onto the walls and the tiles.

They were deep inside the Forgotten Arena now, a crumbling underground structure lost to time, covered in cracked stone, shattered archways, and dust-thick air.

"We should be nearing the secondary relic vault," Jin said, gesturing toward a narrow corridor just ahead. "It's supposed to be past that hallway, beyond the twin pillars."

One of the group members said, "How did you know all that?"

He replied, "Elysia told me about that."

Behind him, the rest of his team followed in cautious steps. Two of their team walked to either side, one gripping a spear and the other a longsword. A tank with a massive shield held the middle line.

Beside him, the team's only mage hovered her hands slightly above the ground, feeling the pulse of mana in the air. The archer took the left flank, arrow knocked, and behind them walked Veyla, their healer.

Suddenly, Veyla paused, her eyebrows furrowing. "Jin," she called softly, her voice slightly tense.

"I'm sensing high pulse mana fluctuations. Something is up ahead… and it's powerful."

Jin immediately raised a clenched fist, signaling a halt. Everyone froze.

"That means something—or someone—is close," Jin muttered. "Positions, now."

The group moved without needing another word.

The tank slammed his tower shield into the ground with a thud, bracing himself and anchoring the front line.

The mage began murmuring an incantation under her breath, conjuring a flickering Flame Ward, a spell that surrounded the party with a faint reddish glow—protection against fire and energy-based attacks.

The archer took a few steps back and climbed halfway up a pile of rubble to gain a better angle.

The two warriors drew their weapons and took positions slightly ahead of the archer, ready to intercept.

Veyla stood behind them all, clutching her staff, her fingers already glowing with healing energy.

But then it happened.

A slight click echoed through the corridor—barely audible, but enough to make Jin's eyes snap wide.

One of the newer students, a younger student, had stepped forward out of formation, his foot landing on a square tile carved with old runes.

"Wait, no—!" Jin shouted.

But it was too late.

The rune beneath Lonn's boot lit up with a dull red glow.

An instant later, the entire corridor shook violently, a tremor ripping through the floor. Dust and tiny chunks of stone fell from the ceiling.

Somewhere above them, a loud crack echoed, and then the air was filled with a screeching roar—a horrible, grinding sound like metal scraping against stone.

Something ancient… and massive… was waking up.

From the darkness of the side chamber to their right, a shape charged out with terrifying speed.

The Ironback.

It was a monstrous beast, standing nearly twice the height of a man, covered in thick, jagged steel-like plates that shimmered in the dim light like tarnished armor. Its head was shaped like a battering ram, with two curved tusks on either side of its jaw.

Its eyes glowed with a dull green light—empty, cold, and predatory.

"Formation hold!" Jin barked, even as the Ironback roared again and slammed into the wall, cracking it further as it turned its attention fully toward them.

"fall back!" shouted the tank.

But the beast was already charging.

It was a Dread rank beast.

It moved like a boulder given life—fast, heavy, and unstoppable.

It rammed into the tank's shield with a thunderous crash, sending a shockwave through the ground. The shield barely held. The tank slid back a few feet, his boots grinding against the stone.

"Flame barrier—now!" the mage shouted.

Flames erupted in a wall between them and the beast, slowing its next charge. The creature roared in fury, slamming its plated body against the flame ward. Steam hissed as fire met metal, but the beast didn't stop.

Veyla rushed forward, glowing hands pressing onto the tank's back. "Hang on—I'm healing!"

Arrows flew from the archer's bow, aimed at the Ironback's joints, but they bounced off harmlessly against its armor-like hide.

"We need to target its weak point," Jin growled, twirling his twin blades. "Eyes or the underbelly—nothing else will pierce that plating."

The Ironback backed up for another charge, its feet cracking the stones beneath.

Jin lowered into a crouch. "Everyone—be ready. This thing doesn't go down easily."

They had triggered one of the arena's ancient guardians. A creature that shouldn't have been disturbed. All because of one wrong step.