The buried airport was a graveyard of steel.
Flames burned beneath collapsed ceilings, metal twisted into jagged fangs, and the scent of scorched wiring hung heavy in the choking air. Every light had died long ago — the only illumination came from the flicker of battle.
Civilians were gone, guided out by trembling hands and hurried whispers. Now only the echoes remained — and the Prime 10 Devil.
It rose from the smoke, a mass of muscle and shadow, ribs like black iron bars, eyes burning a deep, infernal red. The ground warped beneath it. Shadows bled outward in every direction, slicing through the ruins like living blades.
Yuto stepped forward. His katana gleamed faintly in the gloom — not bright, but alive, pulsing like a heartbeat. The golden aura crawled up the blade, warming the chill that had sunk into his bones.
He remembered his sister's final breath. Her hand had slipped from his fingers once. Never again.
"No more running," he whispered, voice raw.
Then louder: "Move!"
The golden flare exploded outward —
Sun Power: Radiant Wave!
The shockwave split through rubble and shadow alike, searing the Devil's limbs in a burst of burning light. The creature reeled, black steam pouring from its wounds.
Sousuke's boots struck the cracked floor a heartbeat later. Electricity screamed around his arms, the Thunder Bolt weapon humming like a live creature.
"Let's see how much you can take!"
Thunder Power: Thunder God's Wrath — Eighth Technique!
The terminal detonated in white light. Bolts of lightning hammered down from the ceiling, each strike ripping through shadow tendrils and shattering the ground. The Prime 10 Devil stumbled, its roar echoing through broken corridors.
But it didn't fall.
It turned.
A shadowed claw the size of a truck came crashing toward them.
Tatsusuke moved first. His blades sang — one cutting air, the other slicing silence itself. Mist erupted from his feet.
Fog Power: Phantom Veil.
The fog swallowed the Devil's strike, turning the blow into a blind sweep that shattered only concrete. Then he vanished from sight, his next words carried by the wind —
"Now, while it can't see!"
He spun midair —
Wind Power: Razor Gale!
Each slash released arcs of compressed air sharp enough to cleave steel. Shadow tendrils fell away like ribbons. The mist turned crimson where they struck.
Akari's spear blazed blue. Her voice trembled — not with fear, but fury.
"Form Eleven… Ocean's Wrath."
Water Power: Ocean's Wrath (11th Technique).
The entire floor ruptured as a spiraling torrent of water burst upward. It slammed into the Devil's torso, flaying shadows from its skin. Shards of bone-black armor scattered like glass. The wave crashed against the walls, swallowing debris and protecting the last barricades where injured civilians hid.
The Devil's roar split the air. Its body twisted, shadow flesh writhing like tar. Then — retaliation.
Shadow Barrage.
Hundreds of spikes erupted from its body, slicing through smoke and flame.
Sousuke reacted in a flash, stabbing his Thunder Bolt into the ground.
Thunder Power: Lightning Cage!
Electric arcs snapped outward, melting incoming shards midair. The smell of ozone burned in his lungs.
Tatsusuke dashed through the haze, cutting what the lightning missed. His fog shielded the weak, his wind struck the enemy. His mind flashed to his mentor's face — the man who'd died teaching him to master both precision and mercy.
He had never forgiven himself.
He didn't plan to.
"Come on!" he roared. "You'll have to do better than that!"
Yuto charged through the smoke, his katana burning like a sunrise forced through storm clouds.
Sun Power: Solar Nova Strike!
He struck — the world erupted in gold and fire. The blade tore through the Devil's chest, light spilling through the wound like molten metal. The ground shook, the air trembled.
Sousuke pushed the attack, lightning chaining through the Devil's limbs, wrapping around its body like a divine executioner. "You're not walking away from this!"
The Devil screamed — but its voice fractured, warped, too many throats speaking at once. It swung a claw wildly, gouging the floor, ripping concrete like paper.
Akari didn't flinch. She advanced, water swirling around her body like armor.
Ocean's Wrath — 11th Form Continuation.
Her strike speared through the Devil's leg, sending a geyser of black fluid into the air. Steam hissed where it landed, eating through the floor.
The battle became chaos.
Thunder against shadow.
Sunlight against smoke.
Wind slicing water, water shielding fire.
And in the heart of it, Yuto felt his sister's voice again — soft, gentle, dying. Don't stop fighting.
He roared her name as he charged.
Sousuke matched him, lightning flaring bright enough to burn his arms.
Tatsusuke's fog turned to slicing winds, guiding them through the dark.
Akari's water spiraled upward, converging with the golden light.
All four attacked as one.
Solar Nova Strike. Thunder God's Wrath. Razor Gale. Ocean's Wrath.
The Devil's body convulsed, torn apart by the combined power. Shadow tendrils exploded in black mist, staining the walls. For a brief instant, the monster's crimson eyes flickered — the first sign of fear.
Then, silence.
The Devil collapsed, slamming into the terminal floor. The ground shuddered. Smoke rose like the breath of a dying god.
The four heroes stood motionless, chests heaving.
Yuto lowered his katana, the golden light fading to a dull glow.
"It's… weakening," he said, voice hoarse.
Sousuke exhaled, lightning fading from his weapon. "Then we hit harder."
Tatsusuke spun his blades, fog curling around him once more. "If it gets back up, it won't get far."
Akari's water shimmered faintly around her. Her eyes were calm, but her hands trembled. "No one else will die tonight."
Then — a low growl.
The Prime 10 Devil twitched. Its ruined chest began to knit together, shadow reforming, pulsing like a beating heart. Its eyes snapped open — twin crimson embers cutting through the haze.
It smiled.
Yuto's breath caught. "It's regenerating…"
The ground trembled again — deeper this time, from beneath. A hollow sound echoed through the tunnels below, like something vast moving in the dark.
Sousuke's lightning flared instinctively. "There's… another one?"
Akari's grip tightened on her spear. "No," she whispered. "Something worse."
The Devil laughed — a guttural, choking sound that filled the silence like oil spreading over fire.
Yuto raised his katana, jaw set. "Everyone—ready yourselves. This fight isn't over."
The four of them stepped forward as one, their powers flaring once more.
Light, thunder, wind, fog, and water converged, painting the ruins in a surreal glow.
And somewhere beyond the dust and fire… a second pair of crimson eyes blinked open.