The flickering light of their campfire barely pushed back the shadows around them. The Ravine's oppressive silence was a constant reminder that danger lurked just beyond the edge of the glow.
Kaito sat alone, hands trembling as the Void's restless hunger pulsed within his chest. He closed his eyes, trying to calm the storm.
"You have to make a vow," Riku said softly, stepping into the firelight.
Kaito looked up, his golden eyes shadowed with uncertainty. "How? What kind of vow?"
Riku crouched beside him. "A Yakusoku is a promise you make to your Seiki—a binding condition that gives it control over your power. It sets limits and balances the cost. Without it, your power will devour you."
Hina's voice came from behind them, fierce. "But what kind of price? You're already drained just by using it."
Riku's gaze was steady. "It can be anything. A memory, a feeling, a part of your soul... something valuable that anchors your power. It must be true—something you can't betray, or the vow breaks and everything goes to hell."
Kaito swallowed hard, memories swirling—his sister's face, the day she vanished, the empty silence at home.
The Void inside whispered again, louder this time.
Feed me… I am starving…
Kaito clenched his fists. "I don't want to lose anything more. But I can't keep losing control."
Suddenly, a piercing howl split the night. The ground shook violently as a new creature crashed through the trees—this time faster, more agile than before, its aura wild and raw.
Riku jumped to his feet, threads extending instantly. "Another beast. We don't have time."
Hina readied her fists, orange aura flaring.
Kaito stood, heart pounding. The Void surged forward, begging for release.
He took a deep breath. "This time… I'll control it."
Focusing on his memories, on the pain of loss, he whispered, "I vow to protect what I have left. To never let the Void consume what matters most."
The hunger inside screamed—then calmed.
A dark mist swirled around his hands, shaping into sharp tendrils of void energy.
The beast lunged.
Kaito met it head-on, tendrils striking with precise, devastating force.
The power didn't overwhelm him this time—it obeyed.
The beast faltered, defeated.
Breathing hard, Kaito smiled weakly. "I think… I did it."
Riku nodded approvingly. "You forged your Yakusoku. But don't forget—it's a promise you'll have to keep, no matter the cost."
Hina grinned. "Looks like you're finally ready to fight as one of us."
The fire flickered, shadows dancing as the Ravine's trials continued, darker and deadlier with every step.