In the beginning, the world was divided into many kingdoms, each ruled by a different race.
The Clover Kingdom of Elves, the Dwarven Kingdom, the Human Kingdom, the Beastfolk Tribes, the Fairy Dominion, and even the mysterious realm of the Dark Creatures—all races lived in a fragile balance of peace.
Seeking to strengthen that peace, the rulers of every kingdom gathered for a historic summit. Their goal was simple: to unite the nations and allow free travel between their lands.
But one king stood against them.
The Dark King, ruler of the creatures of the abyss, rejected the proposal. Blinded by ambition, he proclaimed that his kingdom was superior to all others. He declared that the world should bow before him…and that he alone would rule as absolute tyrant.
The other kings refused.
And so the Great War began.
The Dark King's forces were overwhelmingly powerful, pushing the united armies to the brink of defeat. Just when all hope seemed lost, the Goddess of Life intervened. She summoned a hero from another world, a warrior bearing power beyond mortal limits.
Together with the allied kingdoms, the hero confronted the Dark King.
Their battle shook the world itself.
In the end, the Dark King was sealed away, his armies scattered across the lands. Though remnants of his forces still attack the kingdoms to this day, humanity and its allies have grown strong enough to keep them at bay.
Yet legends whisper the truth:
The Dark King still lives.
Behind the veil of the seal, he searches relentlessly for a way to break free…
The voice narrating the tale turns out not to be a mysterious storyteller, but a woman sitting at the edge of a small bed.
Melda smiled warmly as she closed the storybook, four children gathered around her.
Her daughters—Elsa, the responsible seven-year-old; Anna, the playful five-year-old; and Bliss, the strangely quiet three-year-old—listened with wide eyes.
In her arms lay Arthur, only a week old.
"So," Melda finished with a teasing grin, "if you're good boys and girls, the Dark King won't come to eat you…"
She wiggled her fingers dramatically.
Inside Melda's arms, baby Arthur narrowed his eyes.
Really? My father doesn't eat children, you wrinkly old hag! the newborn screamed internally.
Of course, on the outside, all that came out was a harmless baby coo.
And even if he DID eat children… being good or bad wouldn't save you.
He smirked to himself.
"Mommmm," Elsa complained, pouting, "why can't Arthur sleep with us tonight? He's our brother!"
"He won't be able to sleep with the way you snore," Anna teased, giggling.
"Grrrrrr! At least I don't talk in my sleep!" Elsa shot back.
"You—!!"
The girls immediately fell into an adorable argument. Melda could only laugh. They were noisy, but cute.
"All right, all right," she said gently. "It's getting late. Time for bed."
"Awwww…" Anna groaned dramatically.
Bliss, as always, said nothing—standing quietly with that cold, gloomy expression no one understood from a three-year-old.
Melda lifted Arthur higher in her arms, gave each girl a goodnight kiss, tucked them in, turned off the lights, and stepped out quietly with the newborn.
Melda carried Arthur down the quiet hallway, the soft glow of lanterns lighting her steps. The house had finally fallen silent—no more bickering from Elsa and Anna, no more tiny footsteps. Only the faint hum of night insects filled the air.
She pushed open the door to the nursery.
The room was gentle and warm, decorated with pastel fabrics and small wooden toys carved by the village craftsmen. A faint breeze drifted through the window, rustling the curtains like a lullaby of its own.
Melda leaned over the small cradle and laid Arthur down with the tenderness of someone handling a miracle.
She brushed a thumb across his tiny cheek.
"Stop touching me, woman!!" Arthur screamed internally, scrunching his face in annoyance.
Outwardly?
He only let out a soft baby murmur.
Melda giggled softly.
"You have so much potential… I can already tell you'll grow up to be a fine man," she whispered, smiling with pure, innocent affection.
Arthur stared up at her, blinking.
You can tell already? Of course you can. I am the Dark King's son. The heir to all darkness. I don't expect anything less.
He puffed his chest proudly—well, as proudly as a week-old baby could.
But then—
"You are the great hero's son, after all," Melda said warmly.
Arthur froze.
His smile shattered.
His pupils shrank.
His heart nearly stopped beating.
…HUHHH!? Who's son??
The air around him felt heavier, colder.
The hero's… son? ME? How—!? The son of the man who sealed away my true father!?
A storm of confusion and fury swirled inside his tiny body. But after a moment…
A slow grin crept across his face.
This… this might actually be perfect. If I grow up as the hero's son… no one will ever suspect me. I can destroy him from the inside. I can erase the kingdom from the roots.
He let out a quiet baby giggle—though in his mind, it was the cackle of a future tyrant.
Melda leaned closer, completely unaware of the evil scheming happening in her baby's head.
"Oh dear, you don't seem tired at all," she said with a playful sigh. "Well… then I'll sing you a lullaby."
She took a breath.
And then she began to sing.
Her voice was soft, gentle—like warm sunlight drifting through leaves. It wrapped around Arthur like a warm blanket, flowing into his ears like silk. It was nothing like the "horrid voice" he expected from a human.
D-Don't try to make me sleep with that disgusting voice—! I won't… I refuse… shut up, woman!
He protested furiously in his mind.
But his eyelids betrayed him.
They began to droop.
The softness of her voice tugged at something deep inside him—something he didn't even know he had. As if someone had taken all the chaos and hatred buried in his heart and wrapped it gently in light.
His tiny fists loosened.
His breathing steadied.
The darkness inside him faded into a drowsy haze.
I'm… not… going to… sleep… he insisted weakly.
But his eyes slowly closed.
Melda watched with a tender smile as his breathing deepened.
She leaned down and pressed a soft kiss to his forehead.
"Good night… my son," she whispered.
The words drifted into Arthur's dreams like a warm spell.
And for the first time in his short life…
the heir to the Dark King fell asleep in peace.
The door clicked softly behind Melda as she left, her footsteps fading down the hall.
For a moment, the nursery was silent.
Then—
Arthur's eyes snapped open, glowing faintly with a sinister purple gleam.
He slowly sat up, then swung his chubby legs over the edge of the crib. With surprising agility for someone who couldn't even walk, he crawled down the wooden bars and landed on the floor with a soft thump.
He dusted off his tiny pajamas—mostly for dramatic effect.
You may be wondering, he said inwardly, pacing across the room like a villain mid-monologue, how the heir of the Demon King ended up as the great hero's newborn son.
He smirked.
Well… it's a long story.
Arthur lifted his baby fingers to mimic air quotes.
After that hero "sealed" our entire family, Father began storing mana. For years. And a few weeks ago… he finally gathered enough power to send one of us outside the barrier.
His eyes hardened, remembering.
But our physical forms are far too powerful. So Father could only send a soul.
A proud grin stretched across his tiny face.
My sister and I fought for the honor of escaping first—to break our family free. She's strong. Terrifying, even. But…
He dusted his hands theatrically.
I'm here. That says enough.
He stopped beneath the window, moonlight spilling over him.
Father launched my soul beyond the barrier—and it switched places with the soul of the hero's real child. So the hero's son is currently trapped inside the barrier in my true body… and I'm stuck inside his weak, frail, magic-deficient infant form.
He sighed dramatically.
Thank the Abyss the hero didn't have a daughter. How awkward would that have been? I have too much dignity for that mess.
Arthur stretched his arms, cracked his knuckles (adorably), and rolled his miniature shoulders.
"Time to work," he muttered—though it came out as cute baby babble.
A black-purple magic circle flared beneath him.
Electric sparks of demonic lightning swirled through the nursery, rattling toys, shaking the crib, and making the curtains whip wildly.
The room glowed with power far too dangerous for a baby's body to handle.
But before the spell reached its peak—
pffft.
The storm flickered.
Sputtered.
And died.
Arthur stood in the middle of the room, covered in smoke, looking offended.
"Huh??" he squeaked internally. This body doesn't have enough mana to break the seal!?
He crossed his tiny arms.
Expected. It would take far more power than THIS to shatter a barrier made to imprison my father. Still…
His expression softened with thought.
Apparently this body has two mana cores. One belonging to the hero's son—some disgusting light core—and then MY dark core. But this infant body can only handle about one percent of my real strength.
He slumped dramatically onto the floor.
I guess I'll have to stick around for a while… as Arthur Einshorn. The son of that nauseating hero.
He sighed like a tired old man in an infant's shell.
Crawling back to his cradle, he muttered darkly, Well… a long day awaits. Better rest this fragile body while I can.
He pulled the blanket over himself—
Then paused.
Something felt… off.
A faint creak echoed from the nursery door.
Arthur slowly turned his head.
Three little faces were peeking through the crack in the doorway.
Elsa, Anna, and Bliss. All wide-eyed. All sparkling with sisterly affection.
Before he could react—
"ARTHUUUR!!"
"HE'S AWAKE!!"
"CUTIE!!"
They burst inside like a stampede of tiny wild beasts.
"LET GO OF ME, PEASANTS!!!" Arthur screamed mentally as Elsa scooped him up.
Anna squeezed his cheeks.
Bliss climbed onto him like a silent assassin.
All three piled onto him with endless cuddles.
STOP!! NOT THERE!!! MY RIBS!! THAT PLACE IS OFF-LIMITS!!! TOO MANY HANDS!!! HELP!!! NOOOOOOO—!!!
The scene zoomed out as the three girls smothered their baby brother in affection.
The camera pulled back through the window, rising into the night sky—
where countless stars shimmered peacefully above a world completely unaware that the heir to the Demon King had just begun his new life…
in the most chaotic family imaginable.
Morning sunlight spilled through the windows of the Einshorn household. Birds chirped gently outside. It was peaceful…
Too peaceful for the heir of the Demon King.
Arthur was currently being breastfed by Melda, much to his internal frustration.
This is humiliation of the highest order. One day I shall raze the heavens… but for now… ugh.
Across the table, his sisters watched him intently as they ate breakfast.
Elsa smiled sweetly.
Anna waved excitedly with a mouthful of food.
Bliss simply stared with dead, cold eyes, her spoon unmoving.
Then the bedroom door creaked open.
Out stepped Alfred Einshorn, the renowned hero who sealed the Dark King. His hair was messy, his jaw unshaven, and he yawned loudly like an exhausted dad instead of a world-saving legend.
"Daddyyy!!!" Elsa and Anna cried, leaping from their chairs to hug him.
Bliss remained seated, glowering over her oatmeal.
"You can hug me too, Bliss," Alfred said gently.
"Why would I?" Bliss replied in a perfectly flat tone.
"It provides me with no advantage."
Alfred blinked. "Is she… really three years old…?"
From Melda's arms, Arthur gave a mental thumbs-up.
Hah!! Truly my favorite sister. A warrior of pure darkness.
Alfred approached, smiling.
"And how's my baby boy doing this morning?"
Arthur glared. His eyebrows lowered. His aura shifted.
Don't you dare lay your filthy mortal hands on me.
Alfred reached out to pick him up—
Arthur lifted his tiny hand.
A glowing purple magic circle materialized in the air.
Alfred froze. "…Huh?"
Melda gasped.
The girls dropped their spoons.
Bliss's mouth twitched—perhaps in respect.
"A magic circle? At this age?" Alfred whispered. "That shouldn't be possible…"
Before he could finish—
"INCINERATE."
A colossal tornado of blazing fire exploded from Arthur's palm, engulfing Alfred, blasting him across the room, and tearing half the house apart in a blinding inferno.
The explosion shook the ground. Ash rained down like snow.
The room went completely silent.
Melda, Elsa, and Anna stood frozen in horror.
Even Bliss blinked.
Smoke drifted from the crater where the living room used to be.
Arthur sighed dramatically.
Well… I guess the hero's son's mana core has enough power to keep me afloat. Shame it's nowhere near enough to kill him.
From within the smoke, a figure emerged.
Alfred walked out—scorched clothes, singed hair, and soot covering his face. He coughed a little, wiped a tear from his eye, and dusted himself off.
"W-well…" he said, "that was quite a spell."
His expression hardened into a serious, hero-like gaze as he approached the baby.
"Tell me, Arthur…" he said solemnly.
Melda held her breath.
Elsa and Anna trembled.
Even Arthur paused.
Then Alfred's face lit up like a festival lantern.
"How are you able to use a high-level fire spell at this age without any incantation!? My boy is incredible!" he shouted proudly, grabbing Arthur in a tight cuddle.
Arthur's soul screamed.
Unhand me, foul creature!
He slapped Alfred's cheek with his tiny baby hand.
Alfred froze.
"…He hates me," he said dramatically, tears forming. "As usual…"
Melda walked over and placed a comforting hand on his shoulder.
"Children usually unlock their magic around age eight," she explained.
"All our daughters awakened early… but Arthur…" She looked down at the baby with awe.
"He awakened his at an impossibly young age."
Alfred sniffled, still hugging his emotional wounds.
"But I still love you… even if you despise me…" he whispered to Arthur.
Arthur rolled his eyes so hard they nearly spun out of his head.
I expected more dignity from the man who sealed my father. This is embarrassing.
The hero wiped his tears, beaming with pride.
"That's my boy!! A future legendary hero!"
Arthur gagged.
The Einshorn household quieted down after breakfast, the adults busy repairing the half-destroyed living room, and the sisters momentarily distracted with toys.
It was the perfect opportunity.
Arthur slipped out of Melda's arms, crawled down the hallway with surprising stealth, and entered his target:
The Library.
The room was enormous—towering bookshelves filled with tomes on magic theory, ancient history, forbidden techniques, and Alfred's personal journals from the war. Sunlight filtered through the tall windows, illuminating clouds of dust floating like glitter.
Arthur's eyes gleamed.
Finally. A place worthy of my genius.
He crawled across the wooden floor, pulled himself up by gripping a shelf, and scanned the spines.
"Basic Light Spells
—Level 1"
"Heroic Mana Flow
—Revised Edition"
"The Ethics of Magic
(Why You Shouldn't Kill Anyone Ever)"
Arthur sneered.
Disgusting. Brainwashing garbage.
He reached higher and pulled out a heavier tome with his tiny hands:
"Advanced Light Manipulation and Hybrid Mana Theory."
Perfect.
He opened it on the floor and began flipping pages with alarming speed for a baby. His expression sharpened.
If I combine the light core in this pathetic body with even a fraction of my dark core… I should be able to develop hybrid spells no mortal has ever seen. Spells that will shake the world… and force these humans to acknowledge me.
He traced symbols in the air with his finger. A small magic circle formed—pure white light twisted with faint purple lightning.
Yes… if I stabilize the light mana and invert the polarity before infusion, I could create a—
A shadow fell over him.
Arthur froze.
Something… predatory lurked behind him.
Slowly…
He turned.
Elsa stood there.
Bent forward.
Eyes sparkling.
Smile wide and terrifying.
Like a lion who had spotted her prey.
"Arthur…" she whispered.
No. No no no.
She crouched lower.
"Arthurrrr…"
Stay back, woman. Stay back!!!
She pounced.
"ARTHURRRR!!"
"STAY AWAY FROM ME, FEMALE!!!" Arthur shrieked internally as Elsa grabbed him, lifted him into the air, and squeezed him like a plush toy.
She nuzzled his cheek.
Arthur squirmed violently.
Unhand me! You tiny demon!!
Then Anna burst in.
"OH! It's snuggle time!!"
She tackled both of them, grabbing Arthur's legs, swinging him like a ragdoll.
"STOP!!! NOT THE LEGS!! NOT THE LEGS!!! I NEED THOSE FOR FUTURE WORLD DOMINATION!!!"
And then—
Bliss entered.
She stared at Arthur.
He stared back.
The cold, emotionless girl slowly approached…
And gently tapped his head.
"…Cute," she whispered softly—something she had NEVER said to anyone before.
Arthur's jaw dropped.
Why is the gloomy one the scariest of them all!?
Then she hugged him too.
"NOOOO!! TOO MANY HANDS!!! TOO MANY—DON'T TOUCH MY HAIR!! STOP MOVING ME AROUND!! I CAN'T BREATHE!! THIS IS A VIOLATION OF ROYAL DEMON RIGHTS!!!"
All three siblings rolled around the floor with Arthur trapped among them, limbs flailing helplessly.
Books toppled.
A vase shattered.
Arthur's hybrid magic circle fizzled out as the chaos consumed him.
Just then—
Footsteps echoed down the hallway.
Arthur froze.
Parents.
He immediately went limp.
The sisters stopped attacking him and scrambled to look innocent as Alfred and Melda walked in holding cleaning supplies.
"What's going on in here?" Alfred asked.
Elsa quickly said, "We're just reading!"
Anna nodded. "Yeah! Reading!"
Bliss quietly stood in front of Arthur like a bodyguard.
Melda smiled warmly.
"Aww, how sweet…"
Arthur forced himself to giggle like a normal baby.
"Hee… goo… gaaa…"
Inside his mind?
PREPARE YOURSELVES, HUMANS. ONCE MY MAGIC RETURNS, YOU WILL ALL—wait… STOP SMILING AT ME LIKE THAT, MELDA—AGH, SHE'S PICKING ME UP AGAIN.
Alfred ruffled his hair.
"My boy loves reading already! He's gonna be a genius!"
Arthur internally screamed.
I AM a genius!! And you fools are slowing down my world-conquering studies!!!
But on the outside?
He drooled cutely.
Evening slowly settled over the Einshorn home.
The sisters had finally tired themselves out from mauling Arthur earlier, and the household grew quiet.
Arthur lay in his crib, glaring at the ceiling.
These humans… They interrupt my training. They invade my personal space. They RUFFLE MY HAIR. Disgusting. I should vaporize them all the moment I regain full power. Yes. I'll burn this place to ash…
He clenched his tiny fist with dark determination.
And then—
A soft knock.
He stiffened.
The door creaked open, and a small shadow entered quietly.
Bliss.
Barefoot. Silent. Expression unreadable as always.
Arthur blinked.
She wasn't loud like Elsa.
She wasn't chaotic like Anna.
She wasn't clingy like Melda.
She moved with this strange… calmness.
Bliss approached the crib slowly, her hands behind her back. She stared at Arthur with those cool, emotionless eyes.
For a full ten seconds, neither moved.
Then Bliss whispered:
"…Hi."
Arthur flinched.
Humans never approached him like this.
Careful. Quiet. Respectful.
She pulled out what she had hidden behind her back—a small wooden carving.
A little figurine.
A demon.
Two horns. Little tail. Tiny fanged smile.
It was… shockingly accurate to Arthur's true form.
Bliss hesitated, then offered it to him.
"I… made this. For you."
Arthur's mouth dropped slightly.
She… made a statue of… me?
Bliss added, very softly, "I thought you might… like it."
Arthur stared at the figure.
His small hand moved on its own and grabbed it.
It fit perfectly in his little palm.
Bliss's expression didn't change much, but her ears turned slightly pink.
"…You're always alone," she whispered.
"And the others are too loud. So… I thought maybe you'd want someone quiet around you."
She climbed into the rocking chair beside the crib and began gently rocking it with her foot.
Arthur, baffled, simply stared.
Bliss continued, voice unusually warm:
"You're… different. I can feel it. But it doesn't scare me."
Her fingers gently brushed his hair. "Actually… I think you're special."
Arthur felt something unfamiliar.
Warmth?
No, impossible.
He was the Demon Prince.
He didn't feel soft, warm emotions.
He felt wrath, pride, destruction—
But Bliss wasn't clinging to him.
Wasn't suffocating him.
Wasn't treating him like a toy.
She was simply… there.
Quiet. Calm.
Warm in a way he wasn't used to.
Bliss yawned slightly and leaned her head onto the side of the crib.
"If anyone bullies you… I'll beat them up," she mumbled sleepily.
"I don't know why, but… I like you a lot…"
Arthur swallowed.
This girl… she reminds me of…
No.
Impossible.
He wouldn't think about his past.
Bliss's hand gently rested beside his.
"…Goodnight, little brother," she whispered.
She fell asleep there—leaning against the crib, her breathing slow and peaceful.
Arthur stared at her.
He looked at the demon carving.
He looked at Bliss again.
His chest tightened.
…What is this… feeling?
For the first time since reincarnating…
…he didn't think about destroying the world.
Well… not ALL of it.
Maybe he could spare one person.
Just one.
He turned away quickly, cheeks warming.
Ridiculous. I am the supreme ruler of darkness. I do not get attached to humans. I will crush them all—except…
He glanced at Bliss.
…Except maybe her.
He let out a small sigh and clutched the wooden demon figure to his chest.
"…Tch."
But he didn't stop her from sleeping beside him.
Not that night.