My Special Ability is Growing Muscles

To Ironveil City, Blackgate was not just the frontier outpost that kept watch of the Demon domain and would report the first sight of demons.

To the city, it was a psychological support, a symbol that helped them sleep better at night knowing that Demons would not suddenly ambush them without Blackgate warning them of it first.

Besides, with the shield array active and in good working condition, a marvel of technology that not even S Rank Demons could breach easily, the citizens and soldiers of Ironveil City were able to live their lives normally despite the looming presence of the Domain domain.

This was why the fall of the fortress hit so hard.

The civilians didn't know yet. Afterall, what hit Blackgate was not an overwhelming attack of epic proportions that could be seen from a distance. Rather, it was a surgical strike straight at the heart of the fortress.

Assassinating its Commander crippled Blackgate, and by successfully disabling the shield array, in one swift attack, the Demons managed to cripple Ironveil City even before the battle started.

The civilians may not know this yet, but the upper echelons of the city received the news immediately.

With the news came an immediate psychological gut punch.

The question was… what would follow? How would the Demons move, and how would Ironveil City react?

Well, it was a no brainer.

The dust of Blackgate's fall had barely settled when the earth itself began to quake in a sudden escalation of the encroaching Demon attack.

Kairo felt it first, a rhythmic thump on the ground like a heartbeat thudding against the soles of his feet, then came the sound.

It was a low rumble at first, swelling and surging, right until it was no longer sound but a living roar.

The horizon to the north beyond Blackgate, once empty plains had suddenly turned into a moving mass.

The Demons clearly concealed themselves previously with either a high grade illusion technique or an artifact. But now, with the shield array deactivated, they no longer needed to stay hidden.

"…!"

Kairo felt his teeth clatter against each other in dread as he watched thousands upon thousands of Demon soldiers advance forward in perfect cadence.

Thump! Thump! Thump!

Not even the attack on Nexus Academy was this numerous. That attack was an elite one led by 3 S Ranked Demons.

But this? This was a horde.

The sound made by their marching reverberated like drums of war as clawed feet pounded the ground, their armored bodies glinting with malevolent light.

From a distance, it looked like a sea of black sand flowing across the earth, blotting out the world with its sheer number.

"…!" Kairo gasped, his brain struggling with denial of the reality before him.

And then the chants rose, deep, guttural war songs that rattled the soul, rolling like thunder across the plains.

"Blood for the Abyss!" They roared.

"Death for the Weak!" They chanted.

"Glory for the Demon Race!"

The air itself chilled in the wake of their march.

It was not just the sheer volume of their numbers that boggled the mind though as they marched towards Ironveil City.

Even more visually impacting than the horde of Demons itself was a figure wreathed in black flames at the head of the horde.

His mount, a colossal Hell Horse radiating terrifying A Ranked power stamped the ground, hot steam snorting from its nose as each step it took cracked stone underneath.

Its mane burned blood red, and its eyes were like twin suns of malice.

Upon its back sat a towering warrior clad in obsidian armor etched with infernal runes, the leader of the invading Demon horde. His war blade was as long as three men, its edge glowing with veins of cursed fire.

BZZZ!

The air visibly twisted and distorted from the raw power emanating from this Demon, the distortion more apparent in the region around the blade's edge.

Staring at this Demon, the instructors froze in terror, and one whispered the title every human knew, but few had ever seen.

"An S Rank Demon…!"

He was not of the Demon Council, but his aura alone turned the air heavy, a tidal wave of killing intent pressing down on all who dared breathe before him.

Terror swept like a flood wave as the students staggered. Their knees buckled, and their hands trembled in an expression of raw unadulterated horror.

In the presence of an S Rank existence, a Demon that already took a step into the realm of Gods, mere F and E Ranks like the students stood no chance.

Even the C Rank instructors were inconsequential in the face of this Demon.

Back in the coliseum in Nexus Academy, the reason why Kairo and the other tournament survivors didn't feel this much pressure was because of the presence of Major Pain who shielded them, and subsequently Principal Aelthar.

But now though, nothing protected them from the naturally rampaging aura of the Demon that screamed rage and destruction.

Mira clutched her dagger, but her face had gone pale. "This… this…!" She was tongue-tied; she didn't know what to say.

Whatever she was going to say meant nothing.

All around, freshers screamed as they finally lost it, giving in to their primal human instincts of fear in the face of a predator.

They saw death in the eye, and they lost their minds. Some tried to run before the instructors even barked commands, while others collapsed to their knees, paralyzed by the sheer terror pressing down on them.

But not all broke.

Despite the raw terror that he felt at this moment, Kairo stood, trembling, but his fists clenched. He had already stared down death before, in the coliseum, in the ruins of Blackthorn.

He couldn't stop the fear, his body shook with it, but his eyes burned.

'Dammit!' He snarled in his mind.

Adrain's jaw was tight, his hands glowing faintly with restrained mana.

Selene muttered a sharp chant, her illusions twitching alive around her like protective wings. As for Valek, his teeth ground together, crimson mana flickering at the edges of his eyes.

Just like them, the survivors of the Demon massacre weeks ago also did not crumble despite the raw fear that they felt. They stood like fractured stones holding against a storm, their defiance bleeding into those around them.

Then…

"Back! Fall back to Ironveil!" Captain Helios finally reacted as he roared, his voice cracking with urgency.

The C Rank instructors reacted immediately as they surged to the front, pushing the students into formation.

Their voices whipped like whips.

"Move! Run, you brats! The city is your only chance!"

Students stumbled, but seeing Kairo move, his face grim, his stride unshaken despite his fear, many found courage in him and recovered control over their legs.

Mira sprinted at his side, yelling at the others to keep up. Even Valek barked commands, pride forcing him not to look weak before Kairo.

The retreat turned into a desperate flight.

With the soldiers of Blackgate still valiantly standing their ground against the hundreds of Demons that first attacked, they bought them chance to escape.

But it was not a chance that would last for long.

BOOM!

The ground split suddenly as shadowed blades carved through the earth as D+ and C- Rank Demons pounced upon the fleeing column, having carved an opening through the blockade of Blackgate's soldiers.

"Go!" roared one instructor, slamming his halberd into the ground as his mana exploded in a fiery wall to hold back the surge.

Another ripped open his veins to fuel a suicidal barrier, locking dozens of Demons in with himself as he screamed in defiance.

"For Ironveil!"

They were ready to sacrifice their lives for the students!

The students were too horrified to immediately realize the true gravity of the sacrifice of their instructors as they were shoved onward. They ran, some crying, some vomiting from fear, but they ran because their teachers were dying to buy them seconds.

Behind them, screams were cut short as explosions of mana burst like dying stars, and the sound of steel snapping under monstrous force echoed across the plains.

Then it came.

The S Rank Demon raised his massive war blade high into the air. For a heartbeat, all fell silent. Even the chants cut short.

And then…

KABOOM!

The blade hit the earth with the force of a meteor. The plains split apart, shockwaves rippling out like waves.

The Demon Army roared as one, the sound shaking the skies.

And then, they charged!

…

Within Ironveil City, chaos reigned.

A moment ago, the city was enjoying another peaceful and prosperous day till suddenly, the Demons attacked.

Civilians screamed as alarms blared. Families shoved children into carriages, merchants abandoned their stalls, and soldiers sprinted for the walls only to find the shield array dead.

"Why isn't it activating?! Why?!"

The people of Ironveil watched in horror as the black tide rolled closer, their faith in the fortress shattered.

The city that had always stood strong was now naked.

Kairo stumbled through the gates with the others, his heart torn between terror and fury. Behind him, the instructors' last screams still echoed. And ahead, the Demon Army's roar filled the sky.

Ironveil's defenders scrambled, its shield shattered, its people unready.

War had arrived at their gates.