The vault ignited with red light.
The mirrored chamber trembled as Kairo stepped forward, fox mask glowing, the mark on his wrist flaring like wildfire beneath his skin. Each step cracked the floor beneath him—not with weight, but with will. The glass around him shook.
The Echo Prince raised his arms.
Around the chamber, the mirrors began to spin—showing not just Kairo's past, but possible futures. In one, he died screaming. In another, Yui was consumed by flame. In another still, the world ended under his own hand.
"You think a mask and a mark make you chosen?" the Prince said coldly. "You are a broken blade. A shadow of a promise. And I… am her truth."
Kairo leapt.
The Echo Prince moved like silk through smoke, sidestepping effortlessly. Kairo's punches landed only against air. The Prince's counter came in a blur—a sharp wave of energy from his outstretched hand that slammed into Kairo's chest and hurled him backward.
He crashed into a mirror.
It didn't shatter.
Instead, it swallowed him.
Inside the glass, Kairo tumbled through a world of warped reflections—endless versions of himself, each marked by failure. In one, he lay dying in the ash, clawing toward Yui's outstretched hand. In another, he stood over her body, weeping. In another, he never left the village, and she vanished alone.
"You don't deserve her."
"You failed."
"She doesn't need you."
The voices came from every side.
He sank to his knees.
His mask cracked.
"No…" he whispered.
Then something—someone—touched his shoulder.
A memory.
Yui's voice. Clear. Young. Full of stubborn hope.
"You always get back up, stupid."
His eyes widened.
The mask repaired itself with a pulse of light.
Kairo stood.
And the mirror shattered.
He exploded from the glass in a burst of light, blood trailing from a cut on his cheek but his eyes burning violet.
The Echo Prince reeled back.
Kairo grabbed a shard from the broken mirror—glass and magic fused into a jagged edge—and wielded it like a blade.
Aeska, watching from the edge of the chamber, smiled. "Now you're waking up."
The Prince lunged again, hands glowing with black fire—but Kairo was faster now. The mark on his wrist synchronized with the glass blade. He parried, twisted, and cut.
The blade sliced through the Prince's sleeve.
The illusion shimmered.
The Prince snarled. "You think that was enough?"
"No," Kairo said. "But this is."
He threw the glass blade—not at the Prince—but at the core of the web holding Yui.
The rune threads snapped.
The chamber went silent.
Yui's song stopped.
And for a moment, the only sound was the crackle of dying energy.
She fell—into Kairo's arms.
Her eyes fluttered open. "Kai…?"
He held her tight. "I've got you."
The Echo Prince screamed—not in rage, but in terror. Cracks spread across his form. The mirrors all around began to shatter one by one, light flooding the vault.
Kairo stood, holding Yui close.
And the last mirror exploded behind him.
The Echo Prince dissolved into smoke.
Later, in the ruins outside the Vault, under the starlight that had somehow broken through the ash-choked sky for the first time in years, Kairo sat beside his sister.
She leaned her head on his shoulder. Thin. Scarred. But alive.
"I knew you'd come," she whispered.
He nodded. "Always."
Aeska stood nearby, arms crossed, watching the horizon.
"What now?" she asked.
Kairo looked up at the sky.
"We go west," he said. "There's more out there. More Vaults. More monsters. And maybe… more like me."
He looked at Yui.
"More like us."