Rengoku Hayate has shattered the false image of the "Hero Party," humiliating Ren and his companions before all of Arclight City. Monsters have swarmed from the dungeon, the city is in chaos, and the ancient prophecy of the "Devouring Star" is slowly awakening within him. Now—Hayate steps into the dungeon once more, not as prey, not as a discarded burden, but as a sovereign force returning to take what is his—
The Dungeon Core.
1 — The Dungeon's Breath Calls Him Again
The entrance of the Dungeon of Hellfire roared like the throat of a volcanic beast—molten cracks pulsing along the obsidian walls, heat shimmering in the air like wavering spirits. Screams and clashes echoed from within as soldiers and adventurers desperately fought off the remaining monsters pouring out into the city.
Rengoku Hayate stood before the entrance, black coat fluttering, his long crimson hair glistening with embers from the earlier battles.
Behind him, the city trembled.
Before him, the abyss called.
Hayate exhaled slowly.
"It's been too long… dungeon."
His voice was calm—but beneath it, rage, purpose, and destiny pulsed like living flame.
A massive explosion behind him rattled the ground. A squad of knights toppled as a three-headed Infernal Hound burst through the outer streets.
"L-Lord Hayate!" one knight shouted, bloodied. "We can hold the city walls, but if the core continues its rampage—"
"It won't."Hayate stepped forward, eyes cold."Because I'm taking it."
The knights shivered. Even now, after seeing him single-handedly suppress tens of thousands of monsters and humiliate the city's former "Hero," they still couldn't grasp the depth of his power.
Hayate lowered his hand, gathering a swirl of black-crimson flame.
Hellfire Devouring Art — Ember Collapse.
One flick.
A silent flash.
The three-headed hound dissolved into ash.
The knights gasped in awe.
Hayate didn't even look back.
He walked into the depths.
The dungeon swallowed him whole.
2 — The Hellfire Dungeon Awakens
The moment he crossed the threshold, the dungeon reacted—walls pulsing, scorching winds screaming like dead gods.
*DUNNNN**DUNNNNNN*
A heartbeat.
Not his.
The dungeon's.
And then—
[SYSTEM ALERT]
You are recognized as: Devourer of Floors — Slayer of False Fate.
Dungeon Level Scaling: Increasing to match your growth.
Hell Difficulty Activated.
Hayate narrowed his eyes.
"So the dungeon still remembers me."
He heard footsteps echo lightly beside him—not threatening, more like someone skipping across floating stones.
A tiny figure popped out of a blazing crack in the wall.
"Hayateeee! You're finally back!"
A small girl—barely twelve in appearance—floated before him, made entirely of swirling magma and stardust. Her hair flickered like fire. Her eyes glowed deep blue.
Flare, the Dungeon Spirit he had awakened long ago.
She hovered around him, arms crossed in a pout.
"You left me for months! Do you know how boring it is in here? All I have are monsters, lava, and more monsters! No snacks! No visitors! NOTHING!"
Hayate sighed.
"It wasn't exactly a vacation for me either."
"Oh? You mean getting stabbed, betrayed, almost murdered, walking through other realms, awakening ancient power, crushing the so-called Hero Party, and being worshiped by half the city? Yeah, super relaxing."
Hayate paused. "…You were watching?"
Flare puffed her cheeks.
"I AM THE DUNGEON. I see everything."
He couldn't argue with that.
"Fine. I'm back," Hayate said calmly. "And this time—I'm taking the Core."
Flare froze.
Her molten pupils shrank like burning coals dipped in cold water.
"You… want to absorb me?"
Hayate shook his head.
"No. The true core. The one beneath you."
Flare blinked. Twice.
Then she sighed in dramatic relief.
"Oh thank god. I like existing."
3 — Floor 1 to 10: The Dungeon Changes Its Rules
The flame-lit labyrinth of Floor 1 was silent. Too silent.
Hayate took one step—
—and the entire floor ruptured.
Not with monsters.
With evolving monsters.
Creatures that looked like molten knights rose from the ground, armor dripping with fiery sludge, their swords glowing white-hot.
Flare floated to Hayate's shoulder, whispering,
"Ummm… so the dungeon kind of… upgraded itself after detecting your power."
"Upgraded how?"
She winced.
"Ever heard of something called 'Adaptive Instant Evolution Mode'?"
Hayate's eyebrow twitched.
"No."
"Oh! Because no dungeon is supposed to have it. Like… ever."
Ten molten knights charged at once.
Hayate snapped his fingers.
Hellfire Devouring Art — Star-Eater Burst.
A crimson orb erupted from his palm, expanding outward in a silent implosion.
The molten knights were erased.
Flare clapped.
"Yay! You still kill things in one move! I feel safe again."
"Good. Because this dungeon won't give us any rest."
Hayate moved deeper.
As he walked, Flare floated beside him, constantly chatting, humming, or politely warning him of incoming death traps.
"Watch your step! That tile explodes into lava."
Hayate stepped to the side.
"And that corridor? Full of invisible fire drakes."
He raised a hand.
Slash.
Their corpses dropped from midair.
Flare winked.
"See? Teamwork!"
4 — Floor 11 to 30: Trials of Heritage
The lower floors burned with ash storms and volcanic eruptions, but Hayate moved through them like a blade dancing between falling stars.
Here, the dungeon changed again.
It showed him not monsters—
—but memories.
A ghostly projection flickered before him.
His younger self:
Weak. Powerless. Crying under the fists of classmates.
Hayate's eyes darkened—not with shame, but with wrath.
Flare whispered timidly,
"This layer shows challengers illusions of their past… It's supposed to break their will."
"Break me?" Hayate's voice was calm.
"Impossible."
He walked through the illusion.
The memories shattered like fragile glass.
The dungeon roared—angry.
Floor 20 projected Kaito and the Hero Party laughing as they abandoned him in the dungeon long ago.
Flare glanced up at him carefully.
"You okay…?"
"I don't care about them," Hayate said. "I have already destroyed them."
He kept walking.
Floor 25 projected something else.
His mother's silhouette.
Her fading voice.
"Hayate… survive…"
Hayate's steps faltered for the first time.
Flare gently placed a hand on his cheek, her flame soft and warm.
"You don't have to hide everything."
He closed his eyes.
Then he crushed the illusion underfoot.
"Let's continue."
5 — Floor 31 to 50: Monsters Worth Killing
From here onward, the dungeon no longer played games.
Each monster was a calamity.
Lava seraphs with wings of flame.
Inferno Behemoths.
Volcanic Wraith Kings.
Any one of them could annihilate a city.
Hayate carved through them effortlessly.
A flaming titan swung its molten fist.
Hayate caught it with one hand—
—and shattered its arm.
Another titan lunged.
Hayate stepped forward and severed its head in a blur.
Flare stared in awe.
"You know… I used to think my dungeon was scary..."
"Now?" Hayate asked.
"Now I think YOU should be sealed underground, not the monsters."
"…Thanks?"
"Not a compliment."
6 — Floor 51 to 70: The Dungeon Knows Fear
The deeper they went, the more the dungeon trembled.
Flare gulped.
"This is… weird. The dungeon is terrified. I can feel it shaking through the walls."
Hayate's eyes sharpened.
"It senses the Devouring Star."
Flare floated backward, nervous.
"I thought that power was just a myth…"
"It is not a myth."
Hayate extended his hand.
A black star—tiny, flickering—slowly rotated above his palm.
Born from despair.
Forged through betrayal.
Strengthened by vengeance.
Flare whispered,
"It's… beautiful. And terrifying. Like a star that shouldn't exist."
Hayate closed his fist; the star vanished.
"Let's finish this."
7 — Floor 71 to 99: Hellfire Rebellion
By Floor 90, the dungeon had fully revolted.
Walls erupted violently, floors collapsed into magma oceans, monsters regenerated infinitely.
Flare cowered behind Hayate.
"The dungeon core is panicking! It thinks you're here to destroy everything!"
"I am."
"R-Really?"
Hayate smirked slightly.
"Unless it cooperates."
That made Flare blush bright orange.
"Y-You're so… demanding…"
"Focus."
They stepped onto Floor 99.
And there—it waited.
The Infernal Sovereign, a monster made of lava, shadows, and ancient flame, towering hundreds of meters tall.
It roared—
—and the entire dungeon shook.
Flare panicked.
"That's the guardian! The only thing stopping challengers from reaching the Core! Even I can't control it!"
Hayate rolled his neck.
"Good. I needed something to warm up."
The Sovereign swung a continent-sized arm.
Hayate leapt.
Slash—
A streak of black light carved across the floor.
The Sovereign froze.
Then—
BOOOOOOOOOM!!!
Its body erupted like a volcano, splitting apart.
Flare clapped wildly.
"HAYATE WINS AGAIN! YAAAY!"
8 — Floor 100: The Heart of Hellfire
The deepest chamber glowed with molten gold. Rivers of flame flowed around a crystal the size of a cathedral.
The Dungeon Core.
But it was… corrupted.
Flare gasped.
"N-No… this isn't how it should look. Something's wrong!"
The core pulsed with black cracks—something was devouring it from within.
Hayate stepped closer.
And then—
A cold voice whispered through the chamber:
"Devourer...I have been waiting."
A shadow rose behind the core, monstrous and formless.
Flare screamed.
"That's not part of the dungeon! That's— That's an external entity! Something invaded us!"
The shadow hissed,
"You carry the Devouring Star. Give it to me. Or die."
Hayate's eyes narrowed.
"I don't give my power to parasites."
The shadow lunged.
And Hayate unleashed the star within him—
A swirling black sun, devouring all light.
Flare shielded her eyes.
"HAYATE—!!"
The chamber erupted in a silent, cosmic implosion.
The shadow howled as its body dissolved into stardust.
The core trembled.
Hayate placed his hand on it.
And the Dungeon of Hellfire trembled as one.
[SYSTEM: Core Synchronization Complete.]
[You have gained partial authority over the Dungeon.]
[Dungeon Spirit "Flare" now linked to your soul.]
Flare blinked.
"…Linked? As in… permanently?"
"Yes."
She blushed so hard her entire body glowed cherry-red.
"T-Then I'll… stay with you forever… idiot."
Hayate smirked.
"Let's go. We have a city to save."
Behind them—the dungeon bowed.