The Demon World—an immense, chaotic realm where countless demon races clash, scheme, and thrive.
Above all sits the vacant throne of the Demon King, abandoned ever since the monarch mysteriously vanished years ago.
No successor. No ruler. Only a power vacuum.
And at the border where the Demon World touches the Human World…
A lone boy was being carried through the air.
"Hey, old man—where the hell are you taking me?"
The boy, known until this moment only as Shax Suzuki, snapped, struggling against the demon's iron grip.
The horned demon, Sullivan, ignored him completely, flying with effortless speed toward a distant citadel. Shax scowled. Typical. Not even the courtesy of a reply.
Just hours earlier, Shax had been working illegally on a rundown fishing vessel—forced labor, underpaid, overworked, and shoved into the worst tasks because he was just a fourteen-year-old. He clenched his jaw. If he hadn't transmigrated into this world with a peculiar system, he would have been crushed under debt long ago. The system kept him alive—but only just. And it still wasn't strong enough to be used on this powerful demon, which only made the situation more irritating.
Finally, they landed inside an enormous castle suspended in the sky.
Sullivan snapped his fingers—
Shax suddenly found himself seated in a velvet chair, wearing clean new clothes tailored to his size. The old grime, exhaustion, and saltwater smell from the ship were gone.
"What now?" Shax muttered, unable to hide his confusion.
Sullivan knelt before him, taking one of his hands gently.
"Shax Suzuki," he said with a trembling smile,
"will you become… my grandchild?"
Shax blinked. His mind went blank, then cleared. The setup felt familiar, but changed. Wrong details. Right shape. Off-pattern universe. He had been too busy surviving to consider it, but now—this felt like the end of his suffering.
He exhaled slowly and closed his eyes.
"Grandchild?" he echoed.
Sullivan's face lit up.
"That's right! I've been lonely for so long. All my friends brag about their grandchildren. I want one too! I'll buy you anything. Protect you. Spoil you. Give you a home. Please? Please??"
Sullivan suddenly transformed into a smaller, chibi-like version of himself as he begged.
Shax sighed. The system wasn't warning him. Sullivan wasn't hostile. And the alternative was going back to poverty, exploitation, and certain death.
"…Fine," Shax said. "I'll do it."
The moment the word left his lips, the containment field holding his true, hidden power together snapped with the finality of a collapsing star. It wasn't a verbal agreement; it was a cataclysmic explosion of being.
A blinding flash of corrupted, sickly golden light erupted from his core—the signature of a high-ranking, but morally twisted, divine being. This light was immediately smothered and simultaneously enhanced by a massive, surging wave of primal, viscous darkness—the raw mana of the primordial abyss. The two energies clashed so violently around him that the pavement cracked and the air began to hiss.
Sullivan, for the first time in millennia, took two full, surprised steps back, his chibi smile utterly obliterated by genuine shock.
Shax let out a guttural, strangled cry, the pain of his physical form being instantly reshaped by his hybrid mana overwhelming him. The invisible, spiritual contract dissolved, sealing the pact not on paper, but directly onto his blood and soul.
From his back, eight massive, powerful black wings tore through his tattered jacket. These were the fierce, stylized pinions of a Fallen Seraphim, forged from shadow and cold light. Their edges glowed with faint, runic script that constantly changed, demanding order and judgment.
Then came the mark of his demonic heritage. A single, flawless, obsidian horn began to twist out of the side of his skull, sleek and polished like dark metal. It wrapped around the side of his head, curving gracefully to meet his forehead, forming a natural, asymmetrical demonic crown. It represented raw, unbridled power and ancient will.
His physical aura became a visible, sickening blend:
The Fallen Holy Aura: A cold, demanding, golden radiance, seeking immediate compliance, like an icy sun.
The Primordial Demonic Aura: A crushing, hot wave of darkness, demanding total submission and chaos, like a black hole of pure gravity.
Shax stood rigid, trembling violently, the two powers actively fighting inside him, radiating a contradictory force that warped the very air and caused streetlights to flicker and die. He was a living paradox, a battlefield of divine and infernal power.
"...My stars," Sullivan breathed, his eyes wide with a combination of unbridled delight and profound, analytical shock. "An Eight-Winged Seraphim... the highest rank of the Heavens, corrupted and fallen... and a Crowned Primordial Demon... the deepest authority of the Abyss... in the same, perfect, human vessel."
Shax—now fully transformed—finally opened his eyes. They were a swirling vortex of crimson and gold, the red of the Abyss burning against the light of the Heavens.
"You..." His voice was deeper, vibrating with latent power, laced with the echo of ancient, terrible things. "You knew I was more than human."
"I knew you were special," Sullivan corrected, adjusting his suit and regaining his composure, his smile returning, wider and more genuine than before. "But this, my dear Shax Suzuki, is truly beyond my wildest, most optimistic calculation! The sheer volume of mana, the clash of the highest order and the original chaos! Why, you might not just be a candidate for the Demon King, you might be the most magnificent creature to ever walk this world!"
Sullivan burst into tears of joy.
"Really?! Truly?!"
With a snap of his fingers, magic exploded through the room.
Shax's ragged clothes shifted again—into a black-and-purple demon academy uniform, somehow perfectly tailored to accommodate his massive new wings and his crown-horn. The room redesigned itself into a pristine study, filled with floating tomes and glowing symbols.
Shax stared around, stunned. Magic really is something else...
"Since you're now my precious grandson," Sullivan announced proudly, reverting to his full-sized form,
"I'll prepare everything for you! A proper home, proper meals, proper clothing—and most importantly… proper education!"
"Education?" Shax repeated.
"That's right!" Sullivan clasped his hands together.
"You've lived a hard, uneducated life, haven't you? But fear not—Grandpa has already completed all enrollment procedures for the Academy."
Sullivan's eyes sparkled.
"I am your grandfather now~ The word 'grandfather' truly is wonderful!"
Shax watched the old demon muttering happily to himself.
"A… demon school?" he whispered, a mix of dread and curiosity tightening in his chest. Going to school as a walking battlefield of divine and infernal power... this is going to be interesting.