"Are you immune to the sun?"
Muzan's voice sliced through the air again, colder, sharper.
Willow squirmed in his grasp, her throat burning, her pulse roaring like a war drum. Her hands clutched at his wrist, nails digging into flesh that would not give.
"I… I don't know!" she gasped, tears blurring her vision. "I've never been in the sun—I've never had the chance!"
Muzan's gaze narrowed with disdain. "That is not the answer I asked for."
She felt the pressure increase. Her breath caught. Her lungs screamed.
"Please… don't…" she pleaded, her voice barely a whisper now. "Don't hurt me… please don't hurt my dad…"
Something snapped.
Not a sound in the air, but inside her.
Like an instinct buried deep in her bones had awoken. Like fire blooming in her blood.
Willow's eyes widened. Her fangs ached, her throat burned. And without thinking, she bit hard into the inside of her cheek. Blood filled her mouth, hot, metallic, alive. Dripping out of her mouth.
She shouted with all her strength,
"Blood Demon Art: Vermilion Dragon!!"
From behind Muzan, a monstrous roar echoed through the Infinity Castle.
A serpent of blood erupted from the shifting shadows, a colossal dragon, made of liquid crimson, its scales churning with glowing veins. It lunged toward Muzan with a roar that shook the very walls.
He barely turned before—
CHOMP!
The dragon's jaw clamped down, swallowing him whole everything but the arm holding Willow.
The limb twitched, then detached, dropping her to the floor as the blood dragon recoiled, dragging its captured prey down into the depths of the castle's infinite darkness.
Willow coughed and gasped, clutching at her neck as she fell to her knees, the severed arm twitching beside her.
She didn't hesitate.
"Dad!" she cried, scrambling toward Kokushibo's crumpled form.
He was half-conscious, bleeding, shaking, his skin still cracked like fragile glass. His breathing was shallow.
"Hold on," she whispered, trying to lift him. "I'm getting us out of here."
The castle groaned around them. Walls shifted. Ceilings twisted. Doors opened and slammed shut without a sound. She stumbled forward, dragging her father's weight as best as she could.
But the castle wasn't letting them go.
The air tensed again.
"You worthless pest!" Muzan's voice thundered from the void. "How dare you!"
The ground trembled.
Then—
The floor opened beneath them again.
Willow screamed as they fell.
Below, Muzan stood with his suit torn and his face twisted in fury, a long, barbed tendril already forming from his arm.
Willow looked up and saw her chance.
On a distant balcony above, the biwa lady Nakime calmly observed, her bachi poised over the strings of her instrument.
Another surge of instinct hit Willow, sharper than before.
She reached up, digging her nails into her palm until fresh blood spilled down her fingers.
"Blood Demon Art: Crimson Conquest Modified!" Willow yells, her Blood demon art amplified by the system.
Her blood shimmered unnaturally, threads of power connecting her to Nakime.
The biwa demon froze.
Her eyes widened, lips parting in shock as her own body twitches involuntarily. Her bachi struck a string.
The castle responded immediately.
Sliding doors appeared beneath Willow and Kokushibo, swallowing them again. Muzan's tendril missed by inches, and his roar of rage followed them into the darkness.
They landed hard—this time in a cave. Cold stone. Quiet echoes. No shifting walls. No tendrils. No Muzan.
Just silence.
Willow collapsed beside her father, panting, every breath scraping her chest. She reached toward him, hands trembling, blood still dripping from her fingers.
His eyes fluttered weakly.
"I'm here. I've got you."
Another warmth bloomed in her chest.
She hovered her bloody hand over him, letting instinct guide her one more time.
"Blood Demon Art: Crimson Conquest."
Her blood pulsed, glowing faintly. A soft red light spread across Kokushibo's skin. The cracks slowly began to recede, the bleeding ceased, and the unnatural tension in his muscles faded.
He groaned, then exhaled, slipping into unconsciousness, not pain.
Willow smiled faintly through the exhaustion.
"He's okay…"
Then the world tilted.
And she, too, fell into the dark, her body finally giving in.