The tunnels breathed like the veins of a dying beast. The walls pulsed with a faint blue glow, every ripple of light alive with whispers of trapped mana. The air was heavy—old, metallic, and wet. Their boots splashed softly in the shallow water that ran like blood along the stone floor.
Zentake walked ahead, his lantern swaying lazily from a chain. "This way," he said, his grin sharp even in the dim light. "Smells like money… and death."
No one answered. Omina followed close behind, her shoulders tense, eyes scanning every shadow. Yoshiya walked beside Nogare, his heart pounding in rhythm with the distant hum beneath the earth. It was more than a sound—it was the heartbeat of the city itself.
Nogare's voice cut through the silence. "The lower we go, the older the air. Giggleburg was built over something that shouldn't have been disturbed."
Zentake snorted. "A soul engine, right? Well, let's switch it off before it eats us."
The path sloped down until the light turned violet. Their reflections shimmered faintly in the black water as if the city itself was watching them go.
When they finally emerged, the cavern opened into a cathedral of stone and bone.
---
A massive crystal heart floated in the center, suspended by thick mana veins that pulsed like arteries. Its glow painted the entire chamber in a violent shade of red, beating in slow rhythm. Every pulse sent tremors through the floor.
Nogare stopped. His voice was steady, almost reverent. "Destroy it."
Yoshiya's head snapped toward him. "Who will—"
"You," Nogare said, turning to Omina. "You have the highest firepower here."
Omina stepped forward, gripping her swords. The crimson veins in the walls seemed to mirror the quiet rage beneath her skin. "im ready. "
"That's not your full power," Nogare interrupted.
Yoshiya frowned. "Wait—there are side effects when she uses Berserk. She could lose control—"
Nogare's cold gaze shifted toward him. "You can stop her if that happens. Trust in her, and in yourself."
For a long moment, no one moved. Then Omina's hand rose to her neck. Her fingers brushed against the small, black pendant hanging there—the Berserk Necklace. The metal felt alive beneath her touch, pulsing in sync with the city's heart.
She whispered a single word. "Activate. . Berserk. "
A faint chime echoed, and her aura exploded.
Red light engulfed her body. Her veins glowed like molten glass, and her hair lifted as though caught in a storm. The ground cracked beneath her feet. Even Yoshiya had to step back, shielding his face from the heat pouring off her skin. Her eyes turned gold, her breath ragged and wild.
Omina roared, and the first strike fell.
Twin blades of flame cut through the air, colliding with the heart's surface. The crystal screamed—a deep, resonant howl that shook the chamber. Cracks spiderwebbed across its surface, leaking streams of liquid mana that hissed as they touched the ground.
She slashed again, faster, more violent. Each swing came heavier than the last, her control slipping away piece by piece.
"Omina!" Yoshiya shouted. "Stop! You're—"
But she couldn't hear him. The Berserk state had taken over—instinct and fury consuming reason.
Nogare's voice thundered through the chaos. "Yoshiya! Before she turns on us—purify her!"
"It didn't work last time!" Yoshiya shouted back, panic rising.
"It will this time!" Nogare barked. "Now!"
Omina lunged again, a wild strike that nearly took Yoshiya's head off. He caught her wrist, forcing his palms against her shoulders. "Omina! Wake up!" His voice cracked. "Purify!"
The world went white.
A surge of light burst from his hands, green and gold intertwined. The Berserk aura screamed in protest before shattering like glass. The air rippled with a sound like a thousand voices exhaling at once.
When the glow faded, Omina's body went limp in his arms. Her breathing was shallow, her eyes returning to their soft amber hue. The glow in her veins dimmed, leaving only faint silver lines under her skin.
The crystal heart flickered once—then split open down the center.
---
The explosion that followed was unlike any sound Yoshiya had ever heard. A roar that seemed to tear through dimensions. Shards of mana crystal burst outward, embedding themselves into the walls like glowing knives.
Zentake dove forward, snatching several large fragments into a reinforced satchel. "Don't waste good material!" he yelled, his laughter manic. "This stuff's worth kingdoms!"
The floor convulsed. Blue fire burst from the cracks, lighting the entire chamber in hellish brilliance.
Nogare seized Yoshiya by the arm. "Move!"
They ran, Omina staggering but alive, the tunnels collapsing behind them. The air screamed with pressure as the mana engine imploded, each pulse of the dying core collapsing another tunnel.
Above them, Giggleburg began to die.
The city's upper towers shattered one by one, glowing lines crawling up the walls like veins bursting under skin. Distant screams echoed down the tunnels—demons, humans, and something else all swallowed in the storm.
They burst out into the open air just as the ground behind them erupted. Zentake jumped onto the caravan, tossing the case of crystal shards aboard. Nogare cracked the reins, the wheels skidding over the ash as fire rained from the skyline.
Yoshiya looked back once. He saw the heart of the city—now fractured, bleeding light into the night sky like the final breath of a dying god. Omina leaned weakly against him, her eyes distant, haunted.
Nogare didn't look back. His hands were steady on the reins.
"Day three," he muttered. "Complete."
The fire roared behind them as they vanished into the dark horizon.
And Giggleburg… stopped beating.