Night had fallen over the capital, but the stars seemed dimmer than usual. A strange chill danced on the wind, unsettling even the seasoned mages patrolling the outer walls. Deep underground, beneath the Mage Archives, where ancient spells and forbidden relics slumbered, Kael found himself called by a force he couldn't name.
Not by voice.
Not by word.
But by a pull in his very soul.
The System pulsed within his mind like a heartbeat.
> [Warning: Anomaly Detected]
[Checkpoint Triggered – "The Demon's Echo"]
Kael gritted his teeth, hands trembling slightly.
He'd felt this before—long ago in his previous life—right before everything changed.
---
Descent into Shadow
Escorted by a tight-lipped Wizard King informant, Kael stepped into a hidden chamber carved into the earth. Ancient runes flickered along the walls, reacting to his presence. The air felt dense, heavy with arcane residue.
At the center of the room floated a black book, sealed in red chains of glowing mana.
Its cover pulsed, alive with a sickly crimson hue—almost as if it were watching him.
"You're sure about this?" the informant asked.
Kael nodded slowly. "It's calling me."
He stepped forward.
---
Touch of Corruption
The moment Kael laid a hand on the chained grimoire, a surge of energy knocked everyone else back.
The chamber exploded in swirling mana. Visions slammed into Kael's mind: a war-torn field, shattered stars, a blood-red sky, and shadowy wings beating against the void.
And then…
A voice.
> "You carry power not meant for this world... but you are worthy."
The chains shattered, bursting into mana that fed directly into Kael's core. The grimoire opened on its own, black pages flipping rapidly before halting on a single blank spread.
Then, blood-like ink flowed across the pages.
> [System Sync Detected: Forbidden Class – Anti-Magic Evolution Path Confirmed]
[New Magic Acquired: Demon Grimoire]
[Trait Unlocked: Abyssal Fusion – Grants Kael the ability to integrate demon energy without corrupting his soul.]
Kael dropped to one knee, gasping, the grimoire hovering beside him.
---
The Demon Within
His crimson eyes began to glow—not with rage, but with resonance.
He saw a form materialize behind him—half-corporeal, a towering shadow with wings and a single crimson eye.
The same presence Asta had once felt.
But different.
Less… malicious.
Lyra, Kael's spirit, flickered into view beside him, wary but not hostile.
"This one... chose you?" she asked cautiously.
Kael stood up, steadying his breath. "It's not just a demon. It's a part of the system's deeper code. Something ancient. Buried beneath even this world's rules."
The grimoire floated close to him, pages glowing faintly with infernal power—not cursed, but raw and dangerous.
A weapon… and a secret.
---
Secrets and Shadows
Later that night, Kael stood alone on a cliff overlooking the capital, the Demon Grimoire at his side, closed but humming.
> [System Prompt: Demon Form – Locked Until Checkpoint "Fall of Shadows"]
[However, partial integration available: Demon Veil Cloak – grants speed, magic resistance, and null-field aura.]
Kael summoned it.
A cloak of black mana wrapped around his body, flickering with anti-magic sparks. It moved like smoke and shadow, crackling softly. He flexed his fingers and felt a different sort of power flow through him—one that wasn't light or elemental, but void.
"Balance," he whispered. "Light and shadow… both are needed to protect."
---
Asta's Warning
The next morning, Kael was meditating in the Black Bulls' garden when Asta stomped up, arms crossed.
"You've got something weird going on," he said bluntly.
Kael opened one eye, amused. "Good morning to you too."
"I'm serious." Asta pointed at Kael's chest. "That thing inside you… it's like my devil. But cleaner. Scarier in a calm way."
Kael stood. "I didn't choose it. It chose me."
"You planning to tell the others?" Asta asked, expression turning serious.
Kael shook his head. "Not yet. I don't know enough. I need control first."
Asta looked at him, and after a moment, nodded. "Then let me help you."
Kael blinked. "What?"
"Let's train. Spar. Work the power out. That's how I got mine under control."
Kael grinned. "You're on."
---
The Weight of Power
As the sun rose higher, Kael stood in the center of the training field, Demon Veil Cloak active, facing Asta with both their swords drawn.
It would be the first real test of this new, dark gift.
But even as power surged within him, Kael knew he was still himself.
> A protector.
A brother.
A shield.
And now…
A wielder of light and shadow alike.