Danmachi - Eldritch Apostle

The Goliath began to shake violently as if experiencing a seizure. The sight left Tsubaki completely stunned, as she had never witnessed anything like it before. Niall however, stood steady calmly observing as he waited for the dungeon to reveal its next move.

The monster's skin began to change color, darkening in an instant as though someone had thrown a bucket of paint onto a white wall. Throughout the transformation the Goliath remained eerily silent, its two glowing eyes fixed on the ground below.

Suddenly, its body began to grow expanding into even larger proportions, making it significantly bigger than its previous form. The dungeon had just created a mutated version of the Goliath. It was reminiscent of the event at the end of the first season of Danmachi, except this time, there were two Goliaths instead of one.

Tsubaki was left speechless at the sight of the evolved Goliath. She had heard of dungeon monsters evolving by consuming the magic cores of other monsters, but this was something entirely different.

Not only had the Goliath not consumed any magic cores, but it also exhibited strange behavior before its transformation, almost as if it possessed consciousness. Suddenly, a gust of wind blew past Tsubaki. She managed to resist it by anchoring her katana firmly into the floor.

The Goliath was a Level 4 Monster Rex, typically defeated by Level 5 adventurers with caution. However, this new variation was different.

Tsubaki could feel its strength growing rapidly, and as the smoke around it dispersed, it revealed an even more massive and menacing form than the already humongous creature it had been.

Niall's unshaken calmness in the face of this monstrous evolution impressed Tsubaki. She knew that most adventurers of his grade would be terrified, either fleeing in panic or freezing in fear. Yet Niall simply stood there, unwavering his gaze locked onto the monster's glowing eyes.

"Niall, that monster isn't normal! Let's run and gather proper reinforcements to kill this bastard!" Tsubaki urged, her voice tinged with desperation.

She heavily doubted her ability to fight this new variation of the Goliath. Even more, she had little trust in Niall's capabilities, having heard he was two levels below her. Risking both their lives seemed reckless, and retreating was clearly the safest option.

Niall glanced back at her his face as stoic as ever. "Let me fight my boss fight. Go away until I finish it—don't interrupt the grind," he said, his words carrying a hint of mockery despite the overwhelming danger surrounding them.

"Have you gone mad?!" Tsubaki exclaimed, her voice filled with worry and disbelief. The sheer absurdity of Niall's calm demeanor in the face of such danger left her flabbergasted.

Realizing he was completely serious, Tsubaki decided her only option was to drag him away by force. As she moved to grab him, the ground beneath her suddenly gave way. With a startled cry, she fell through the collapsing floor to the level below.

Niall turned his head slightly, side-eyeing the hole that had swallowed Tsubaki. Moments later the hole began to repair itself, the dungeon's mechanisms working quickly until the floor was restored as if nothing had happened.

"So, you're eager to face me alone huh?" Niall muttered, addressing the massive creature before him. "I can't wait to meet the one controlling this dungeon, I know you can hear me."

The Goliath, which had been motionless seconds ago, let out a deafening roar seemingly enraged by Niall's taunting words.

Niall however, refused to activate his Hastur Cloak. The ability while powerful, had become redundant for him since acquiring regeneration. 

He expected the Goliath to charge at him like a mindless beast but instead, the monster took a deliberate step back and tilted its head behind it. Niall carefully observed the creature's unusual behavior, trying to discern its next move.

A massive ball of light began forming above Goliath's mouth, reminding Niall of something straight out of the Naruto series. Recognizing the imminent danger, Niall immediately pushed his muscles and leaped into the air.

In a split second, the Goliath moved with incredible speed, faster than any adventurer below Level 5 could hope to follow. It thrust its head forward like a missile and unleashed the energy ball toward Niall's position. The massive projectile hurtled through the air like a bullet, and Niall knew that if he were hit he'd likely die instantly, leaving no chance for his regeneration to save him.

The energy ball smashed into the ground with immense force, shaking the entire floor violently. The resulting quake rippled through the dungeon, causing tremors above and below.

Adventurers on the floor below clung to whatever they could to avoid falling, while the citizens of Rivira, confused by the unusual disturbance began to panic.

Meanwhile, before that Tsubaki had landed safely on a bush below, spared from injury by sheer luck.

"Tsubaki, don't tell me he's fighting that monster all by himself! What level is he, 5? 6?!" Welf exclaimed in alarm, throwing questions at her as he noticed her tense demeanor.

Gripping her katana tightly Tsubaki remained silent, her mind racing. Her sudden appearance had already left her group bewildered, but her explanation left them even more shaken. Despite holding onto some hope for Niall, the violent earthquake above convinced them that he had met his end.

"Don't tell me he's already dead!" Welf said, his voice heavy with guilt. He hadn't known Niall for long, but something about the boy's presence had left an impression on him.

Tsubaki sighed, her frustration and helplessness evident. "Looks like we'll have to call Loki Familia. That thing up there is a new variation of the Goliath—a kind I've never seen before, especially not in a Monster Rex."

She glanced at the floor above where she'd fallen and said a quiet prayer for Niall's soul. Though their acquaintance had been brief, she felt a small connection to him one that made his apparent death weigh on her. Now, her priority was to gather reinforcements and inform others about the new threat to avoid further casualties.

However, what disturbed her even more was the dungeon's involvement. The hole that had dropped her below was unnatural, and there was no known monster that could create such a phenomenon. It felt deliberate as if the dungeon itself had been trying to remove her.

"Stand up and get ready to move," Tsubaki commanded her group. "We're going to inform the city about the situation on the 18th floor and the Goliath mutation. Afterward, we'll send a message to Loki Familia. I doubt any of the townsfolk here in Rivira would dare risk their lives against that monster."

Her group nodded, and they began heading toward the city.

Back on the 18th floor, the aftermath of Goliath's attack was clear: a giant, smoldering crater marred the ground, its edges torn and scorched. The sheer power of the energy ball had left destruction in its wake, capable of seriously injuring even a high-level 6 adventurer.

The smoke gradually cleared, revealing the Goliath standing amidst the wreckage. It stared at the crater, its glowing red eyes scanning the scene. The attack had been so devastating that the monster assumed its target was completely obliterated. Confident the battle was over, the dungeon began preparing to recall the Goliath.

But then, from above, a figure descended slowly, its silhouette illuminated by two glowing green eyes. The Goliath froze in confusion, its gaze locked on the adventurer it had presumed dead—alive and now airborne.

"You'll answer for that attack," Niall said ominously, his voice cold and resolute. His gaze aimed at Goliath as an Eldritch Blast swirled menacingly in his left hand.