Heavy Metal [ A Monster Evolution LitRPG ]

“Don’t let them through! Use the oil!”

The order rang out like a thunderclap across the battered battlements. Several adventurers sprang into action, dragging barrels toward the edge of the wall. Thick, dark liquid sloshed violently as they pried the lids open. The sharp scent of tar and pitch filled the air.

Rusty was caught off guard by the strange, viscous substance. Unfamiliar with city defense tactics, he had no idea what to expect. But he was about to learn that there was more to city defense than he could have imagined.

"Archers, get your flame arrows ready! On my mark!"

‘Oh?’

Earlier, a different set of arrows had been prepared. There weren’t many, and each had been soaked in a sticky raisin-like mixture. Rusty didn’t need to do anything as before he could react, the young adventurer who had been shielding him stepped forward, handed him one of the arrows, and lit its soaked tip with one of the torches that were mounted on the wall. It burst into flame almost instantly and burned close to the intensity of a lower-grade magical spell. 

Below, the orcs charged forward, screaming as they brought the battering ram closer to the eastern gate. The metallic skull at the front gleamed wickedly in the firelight, clearly created to intimidate its foes. The wooden palisades around the gate were now weakened and the monsters were able to surge through. If the monsters managed to get their ram in place, the gate would not last for long. 

Finally, when the moment came, the defenders tipped the barrels. Thick globs of boiling oil spilled from the walls, cascading down like a waterfall of sizzling darkness. The liquid splashed over the orcs at the front, hissing as it met their flesh. Screams tore through the air, terrible and raw. The creatures writhed in pain, flailing wildly as they caught fire or were scalded by the heat.

"Now!"

Flaming arrows were launched into the sky. Rusty nocked his on the string and let it fly. It soared in a graceful arc before landing true. The instant it struck the oil-soaked grass, flames erupted. A wall of fire roared to life with a violent whoosh, turning the battlefield into a raging inferno. More arrows followed, sparking fires along the winding trail of oil that had spread unpredictably across the uneven slope.

The Orcs closest to the gate screamed as they burned, their flesh blackening. Some tried to stop, but momentum pushed others forward. Those carrying the battering ram stumbled, one tripping into the fire and dragging the rest with him. The ram crashed to the earth, half in the flames, catching fire as the wood hissed and cracked under the heat.

“YES! That’s it, keep the fire going!” 

Their leader shouted as they watched the monsters burn. Panic had given way to hope, but the fight was far from over. These weren’t humans. They were monsters, and their thick, leathery hides could withstand more punishment than any soldier could expect.

Some of the front-line orcs had fallen, their bodies mangled and charred, turned into grotesque pin cushions filled with arrows. Yet more kept coming. For every one that died, another stepped forward to take its place. The battering log was lifted again and again, each time with renewed force, as fresh orcs surged forward to carry the assault.

‘This is… not that great…’

Rusty kept firing arrows at the oncoming orcs, but a nagging realization began to creep in. Something was off. Despite the chaos and the number of monsters falling, he wasn’t gaining much experience. These were supposed to be E-rank creatures, but the experience points he received felt more like what he’d get from F-ranks.

It didn’t take long for the reason to become clear. Too many people were attacking the same targets, and the experience had to be split among them, and with Gleam as well. This was the first time he was fighting in a large group and this was quite a downside. 

He had assumed this battlefield would be a goldmine for leveling up, but now he saw the truth. If he wanted real progress, the dungeon might be a better option. Out here, unless he fought monsters alone, there wouldn’t be much growth.

He scanned the battlefield again. The oil-fire wall was holding… for now. But the orcs were adapting. The ones in the back had begun tossing charred bodies aside, creating a crude path over the flames. A few even began digging with clawed hands, trying to redirect the burning oil or smother it with dirt and debris.

Their arrows were being deflected by the Orc’s massive tower shields, which, even while burning, still managed to protect the shield-bearers. To make matters worse, a strange-looking orc had appeared among their ranks. He wore different garb from the others and had a talisman made of small skulls. He chanted continuously while other orcs surrounded him in a tight formation.

He was not the leader, but his presence was clearly important. Magic radiated from him, and with every chant, some of the flames faded while nearby orcs began to heal. He resembled the support priests used by humanoid forces. If he stayed in the fight, defeating the orcs would become much more difficult.

‘Can I get him from here…?’

Rusty glanced around. Everyone was focused on the front lines. No one would notice if he pulled an arrow made of twilight steel, and they certainly would not see him wrapping it in darkness. With a few ordinary arrows in hand to hide his movements, he activated his storage and retrieved the special arrow. Calmly, he nocked it and aimed toward the orc who was likely a shaman. The creature was still chanting, completely unaware.

Once Rusty was certain no one was watching, he let the arrow fly. It moved silently, cloaked in a darkened aura that absorbed the torchlight and kept it hidden from view. While his darkness element did not add much raw damage to the projectile, it had other properties. One of them was the ability to inflict a weakness status effect, but more importantly, it had an interaction Rusty had recently learned about.

As he had studied elemental magic with Aburdon, he discovered that darkness carried a secondary trait: the ability to unravel basic mana. Rusty had hoped the shaman would use a mana barrier, and sure enough, as the arrow approached, the creature raised one in defense.

The arrow, shrouded in shadowy mist, collided with the barrier and tore through it with ease. The mana dissolved on contact, unable to hold its form. A moment later, the arrow embedded itself deep in the shaman’s neck, hitting its mark with deadly precision.

‘Ha, now that’s way better!’

It was a lucky critical hit that pierced through the monster’s neck. Rusty had aimed for its head, but the orc shifted slightly at the last moment. Fortunately, the arrow still struck true. Boosted by his Power Shot skill, the attack was enough to instantly take down the only support monster among the orcs.

With the shaman gone, the enemy no longer had any meaningful healing. However, that did not mean the battle was over. The oil reserves were limited, and their side of the barricade was understaffed and running low on supplies. 

The fires began to fade as the orcs threw dirt over the flames, smothering them bit by bit. The battering ram finally started its relentless advance until its metal tip slammed into the wooden gates. With each impact, the doors shook as the orcs bashed their way forward.

At the same time, others had begun climbing the city walls. Rusty had no choice but to grab one of the pikes that had been left nearby. Bracing himself, he moved to intercept the attackers, thrusting the weapon downward in an effort to stop them before they could climb over the edge.

‘This isn’t bad…’

While others around him panicked, Rusty remained focused. His only thoughts were on defeating more monsters. The climbing orcs were easy targets, and with a few well-placed thrusts, he managed to knock one off the wall with little effort.

His allies, however, did not share his composure. Some failed to land decisive blows, while others fumbled entirely, losing their weapons in the chaos. One orc managed to slip past the defenses and tossed itself at the adventurers stationed there. 

‘What are those idiots doing!’

Aburdon commented as they watched the orc tackle one of the adventurers down. He bit his face while other people attempted to save the man from certain death. They started stabbing it with their swords and spears, yet the monster continued to bite down even while critically injured. 

“He… he’s dead…”

The monster was slain but even after they pulled him off the man the damage was done. Blood soaked the stones beneath them, and the adventurer’s face was barely recognizable, torn and shredded beyond saving. Gleam darted forward, trying to cast a healing spell, but her magic could only take care of shallow wounds.

“ ( • ᴖ • ) ”

“He’s gone… and we could be next…”

The three F-rank adventurers stationed with Rusty were momentarily frozen. It was clear they had not witnessed much death before. Their hesitation proved costly as another orc managed to climb the wall a short distance away, right where Oliver was supposed to be holding the line with his spear.

“W-watch out!” 

The orc lunged forward, charging straight at the girl with feline ears. She turned, eyes wide, and screamed as the creature’s muscular hands reached for her head. But just before it could grab her, a metallic hand intercepted the green fist.

It was Rusty. The orc struggled to break free, but Rusty's strength held firm. With a powerful motion, he slammed the creature to the ground, then drew his sword. He quickly delivered a series of sharp, brutal slashes to the orc’s head and torso. The monster thrashed and tried to fight back, but it was quickly overwhelmed.

The three adventurers backed away, wide-eyed, as they watched Rusty slaughter the green monster in a one-sided display of brute force. Blood splattered across the stone as the creature screamed in agony, but Rusty did not stop until it lay motionless. When the fight was over, he slowly turned to face them. His gaze was sharp, his expression unreadable. He pointed toward the spot where the other adventurer had fallen and finally spoke.

"You three, go there. I can hold this position on my own."

“But…”

Oliver started to speak but quickly fell silent when Rusty tilted his helmet in his direction. The silent gesture was enough. The three adventurers exchanged glances, gave a brief nod, and turned to leave.

“T-take care and be careful. Thank you.” 

Rika said, offering a quick bow before hurrying after the others. It seemed they had misunderstood Rusty’s intentions entirely.

‘Nice… all of them are mine for the taking.’

He had not saved the girl out of pity, nor out of some sense of heroism. His only goal was to secure every experience point he could. If the others had stayed, he would have been forced to share the kills. There were not many orcs left now, and he intended to slay as many as possible while he had the freedom to do so.

Soon, the battle resumed. The clash of steel and the howls of monsters echoed once more across the walls. Rusty now stood alone on his section of the battlement, silently waiting for the next opponent to climb into his reach. Below, the battering ram continued its relentless assault on the gate. With each heavy impact, the wooden doors groaned and splintered, and Rusty could tell it would not be long before the monsters broke through.

His sword came down in a clean arc, decapitating another orc as it climbed over the edge of the wall. Rusty briefly wondered why the walls were even built this way, as they were full of holes and uneven surfaces that the orcs could scale them with ease. Then again, it worked to his advantage. Since they needed both hands to climb, they couldn't carry weapons, making them far easier to dispatch.

‘Strange… these orcs feel weaker than the ones I faced in the dungeon…’

The experience they gave was far less than what he had earned from slaying the shaman, and about the same as the E-rank orcs he had encountered in that earlier dungeon. Something felt off. These creatures fought like they had never been in battle before. They moved clumsily, charged head-on without strategy, and barely used their limbs properly.

With another swing of his sword, Rusty sent an orc’s head flying. But before he could fully reset his stance, a deafening crack split the air. The eastern gate shattered. Splinters burst out like shrapnel as the orcish battering ram finally broke through. The defenders atop the wall staggered, some gasping in horror, as the monsters forced their way in. One orc shoved its face through the opening, snarling as it scrambled to squeeze inside.

‘Finally!’

While the other adventurers froze in fear or disbelief, Rusty felt only excitement. The orcs scaling the walls came too slowly, one at a time. But if they poured in through the gate, he could cut them down freely. Without hesitation, he bolted toward the breach. Ignoring the shouted orders of his commander, he leapt from the wall. His feet hit the ground with a solid thud, his sword already drawn and ready.

The monster locked eyes with Rusty through the narrow slit of his visor as it forced its way through the broken gate. From where he stood, he could sense there were at least a dozen more waiting behind it, likely even more beyond view. With the gate breached, all of them would have to funnel through the narrow opening. The side walls still held, preventing a full invasion for now.

Rusty took a step forward, ready to meet them head-on. But just then, something unexpected happened. A horn sounded. Its deep tone echoed like thunder across the battlefield. Every orc froze. Those at the gate halted mid-charge. Even the ones halfway up the walls paused, nostrils flaring, muscles tensed as if waiting for something unseen.

‘Hm? What's going on?’

To his astonishment, the orcs began to retreat. One by one, they backed away from the breach, their aggression seemingly vanishing. It was as if a dungeon core had issued a direct command to pull back. Rusty watched them go, his sword still in hand, a hint of disappointment settling over him as his bags of experience points just left, leaving him in a state of shock.