I wear the mask that took me days to craft, cool as lacquered moonlight against my skin, and grip my artifact—my beloved Long Halberd, Nandu, a river of steel in my hand.

I yank off my self-imposed seal, Azure Coffin Exile—a black collar like a ring of midnight—and unbar my Authority as the Demon King’s Firstborn.

Power surges up like a tide at new moon, heavy and salt-sweet, filling my bones.

I stand within the domain of Shadow, my mind sinking like a stone into the deepest Ocean of Darkness, fingers closing on my Authority, and I trigger it like a storm breaking.

Within my borders, I—Andor—am sight and will both, a god reflected in ink.

A faint disturbance trembles to my right, ripples whispered by Shadow to my ear, and I don’t take time to think—I swing the Long Halberd, wind hissing, yet see nothing; the blade tears only a small drifting leaf.

“No one…?”

I breathe the words like mist, and then the air around me prickles with more disturbances, coming from every direction, a tightening net with no escape.

But why would I retreat?

Andor is the strongest, a mountain under lightning, still and unbroken.

I keep the Long Halberd moving, answering sound with steel; if there are a thousand strikes, I block a thousand, and return a thousand; if there are ten thousand, I block ten thousand, and return ten thousand, rain for rain.

One hand is plenty; at this level, it barely counts as play, a cat batting at falling petals.

The earth explodes, the forest breaks, and space itself keens like a wounded bird; no concept domain in play—only the gale borne by the Long Halberd, a typhoon that can shred all things.

This is the might of Andor, Son of the Demon King—an echo, faint yet bright, of Endless Demon King Andreas and his world-ending hand.

And then a single leaf lands on my shoulder, soft as a sigh, yet it slips clean through my defense mesh.

“How…”

“My baffling master, don’t tell me you’re about to mutter, ‘Even without using Authority, how could a leaf break my defense?’ Such boneless whining, really?”

Ah. Called out.

But… it’s enough. If I keep going, Vega will get anxious.

I stop the halberd’s empty dance; nothing struck but that leaf, while Shadow keeps feeding me disturbances like rain on a drum.

“Come out. That’s enough.”

Leaning on the Long Halberd like a traveler’s staff, I call out:

“Vega, I’m leaving the rest to you.”

“You wreck the terrain yourself, and then—so shameless—ask someone else to fix it? How do you keep a straight face?”

Her expression had soured with every swing I took; now veins stand on her brow like small black snakes.

“Didn’t you say we could train freely here?”

“I said ‘train,’ not ‘level the landscape’!”

“Wrecking the terrain is part of training!”

Yes, I was just bored and flexing, no enemy anywhere; even that leaf was staged by me.

“…”

“…”

We glare at each other, a childish staring contest under a dusty sun—whoever looks away first loses.

Fine. I concede. I glance aside, quick as a bird.

“Sorry. I’ll have you repair the terrain.”

“That’s not the real problem, my master who shifts terms to dodge work. You know your antics draw adventurers like moths, and then our painstakingly built base gets exposed. You know—”

“I know, I know. If exposed, the base loses value. I know already.”

Vega exhales a long sigh, a cold breeze that threatens the roots. Don’t sigh too much; you’ll lose hair.

“I don’t know about hair, but I do know the culprit is my thoughtless master. Why do things so annoying?”

Mm… let me think.

“Probably because my hands itched. I’ve been using the Greatsword too much. I missed Nandu.”

“That’s no excuse for—whatever. My meddling master, next time tell me. I’ll find you a place where you can go all out.”

“Mm… I want one now.”

“My over-energetic master, please wait in the hall of the undercroft, all right? I’ll come as soon as I fix this ground.”

If I keep joking, Vega really will snap; better put away the smile and be serious.

“Then… I’ll stop bothering you.”

“That’s best, my trouble-seeking master!”

She speaks through gritted teeth, poison-wet, suited to her title, yet you can hear how truly angry she is, a thistle of heat.

Mm… I did push too far.

My finest, most capable, stone-faced maid—Vega. Even with a workload that would break mountains growing heavier, her proper face stays the same, as calm as winter glass.

She lifts a black short strand from her brow like brushing off soot; no incantation—just magic through the domain of Shadow. Soil folds back like a rewound film; broken trunks and tangled weeds graft clean; they may still wither later, but for now the forest stands lush and green, a bowl of dark jade.

“I still need to do a lot of finishing work. My idle master who stands around as if that’s labor, don’t give me that ‘I’m close by so I’m helping’ look!”

Vega’s words have barbs, but consider her origin—born from the Ocean of Darkness, the Opera-House Fiend. Even bound to me, she’s still Vega the Vicious; that she holds her temper this far deserves praise, like a storm choosing not to break.

“Then… I’ll go.”

“…”

She keeps working, too weary to answer, a millwheel turned by night water.

So unfriendly. And she saw through my little ploy. I should head back.

“I’m really going now…”

“…”

Vega snaps her head around, but before she can scold, I sink into Shadow like stepping into a cold lake, and slip away.

…

I, Andor, Firstborn of the Demon King, strongest among the Son of the Demon King, was betrayed and gravely wounded while leading twenty-three siblings to invade the mortal world, a banner undone in midnight rain.

So I decided: even kin, even friends—I won’t trust lightly, and I won’t spare the blade.

The day I am crowned is the day all traitors are tallied, a ledger written in iron.

Mm. Don’t mind that—mostly jokes.

I keep pulling items from Shadow and setting them in neat rows, like stones on a riverbank, and amuse myself with the thought.

“My master who loves giving others trouble, what are you at this time? Ah, surely something that won’t help our plans to conquer the world.”

Mouthy. I’m not that annoying.

“Actually, I’m sorting the black tech we currently hold. Like that rope I gave you to counter the enemy’s high retainers.”

Last time, to honor the pact with Wisdom God Haydon, I asked Vega and Berenz to unseal an ancient monster, a primal being—the Sky-Bearer, Beozwuf. Because the task mattered, I gave them a rope that instantly severs a creature’s link to Authority Domains, a clean cut like ice on a vein.

They met my greatest rival—the Demon King’s trueborn daughter, Anna, who holds Slaughter. Thankfully, with my black-tech rope they snared Anna’s high retainer, Nan Lu; then Berenz was sacrificed; at last, Beozwuf’s seal broke like a glacier calving.

“That rope… if I recall, my master who talks nonsense said the Founders made it to seal the Ocean of Darkness—an isolating rope for concept domains?”

My all-purpose maid Vega, in bed or out, in chores or wars—she satisfies me in all things, save for that tongue sharp as broken glass.

“If you’d skipped calling me a blatherer, that explanation would’ve been perfect. And this—seventeen hundred years ago, while researching magic, a great mage accidentally forged a directional annihilation spell. It drinks little mana, but uses annihilation theory to ramp its force to catastrophic levels. He saw at once humans shouldn’t wield it. Even if chain-annihilation is vanishingly unlikely, once it spreads, mortals will one day end their own world.”

“And the result?”

Vega asks, curiosity bright as a moth over a flame.

“Obviously they failed to seal it completely. Can’t you tell?”

I point at a gorgeous crystal orb, a spell-structure turning inside like a galaxy, and shrug.

“And here—this is a monster-conversion device. It skips killing and Ocean-of-Darkness conversion, and directly turns all living things within a hundred kilometers into Demonfolk retainers. They’re mindless lower retainers, but the cost-efficiency is sky-high.”

“Really? How could an alchemical device be that strong? That’s impossible!”

By today’s standards, yes—impossible magic, a stairway missing steps.

It’s rare to see Vega rattled. Very cute. Maybe I should kiss her.

Mwah.

No reaction to the kiss; her amazement lags behind my collection’s shine.

Probably because Vega’s fondness for me is already high; a simple kiss won’t draw out a special cute response. It makes me happy, and a little wistful, like dusk after fireworks.

“It’s real. The Sorcerer Emperor built it to explore how the Ocean of Darkness might infect the Golden Age before it manifested. It’s a failure piece, and a bit different from us Demonfolk. But it’s also a stroke of genius; they helped us learn the dark can be used this way.”

A good deed curdled into a colossal mistake, a sweet fruit with poison at the core.

There’s also a cursed ring that steals the strength of whoever wears it, a hungry moon around a finger.

A toxin that grows more ferocious the more you antidote it, a snake that bites harder when you pull it off.

A Demon Blade that kills without counting as harm inflicted by its wielder, a shadow that leaves no footprint.

Forbidden magic that burns the soul to strengthen the body, a candle trading tomorrow for today.

A feathered arrow that, once loosed, will surely slay a wise king, a single streak of winter through a crown.

A magic sword that drinks the souls of those it kills, a black well with no bottom.

A dagger that kills in one strike, a raindrop that turns to ice at the heart.

A necklace that hypnotizes and makes others submit from the heart, a silver loop that whispers the warmest lies.

A terrifying alchemical organism that devours resources and splits at speed, a locust swarm with a scholar’s hunger, draining armies and granaries alike.

A lost artifact whose blade’s flame burns away everything, a sun caught on steel.

A malign spell that resurrects the dead unconditionally, but twists their temperament, a mirror that returns the face but not the gaze.

A viral concentrate that turns anyone bitten by the infected into a zombie, a midnight fever that walks on teeth.

A wondrous key that opens everything—physical locks, the darkness in hearts, and the body’s latent gates—a little bone-colored promise that fits every seam.

All of them are my collection, rare and bright, curios laid like stars in velvet. Each item hides a legend; each name yields an old secret, like dust puffed from a sealed book.

“I always thought my lazy master did nothing all day. Who knew you’ve been bearing infamy for the Demon King Army, working in silence?”

Her voice gathers a tremor, a stream breaking through a tight dam. That proper blank face begins to crack; she wipes tears, rain on marble.

“I’m so sorry, my magnanimous master. You forgave my years of slight, and even indulged me. I—I…”

I’m a little embarrassed. These are just hobby collectibles, picked up in my leisure, not searched out for war or conquest.

Back in the Demon Realm, they mostly served to show off to my siblings, to feed my pride like a warm coal.

I can’t say that to Vega in this mood. If her favor drops, that’d be bad—snow in spring.

So I spend a long while comforting her, words soft as night reeds.

“But… my great master—how did you get all these legendary tools?”

Vega finally strings a full sentence, but some questions shouldn’t be answered, doors that stay shut.

I narrow my eyes, pat her head light as falling ash, and speak plainly:

“Vega, you know this. A Demon King always pulls out era-leaping black tech to vex a Hero—but you never ask how he got it. Otherwise the Demon King stops being mysterious, loses his charm, and becomes just a stronger villain. That’s not a Demon King at all.”

That’s the thing about being the Demon King: boons just fall into your lap with the crown, no why needed. As long as I don’t party with the Hero, my skill points and tech points won’t bleed away.

…Alright, if that’s your will.

Also, Vega, this one, this one, and this one—keep them for now. I’ll teach you when to use them, and how.

Is it really okay to hand me things this precious?

Because if trouble hits like a storm, I won’t have time to issue orders. So you hold them first. Alright, we’ve got bigger things to do. Come, I need your help.

I stepped into a magic circle, its pattern glinting like frost-lace, akin to the one I used to summon the other maid, Berenz.

First things first—let’s pull Berenz back from the dark river. There’s a mountain of work only her hands can handle.

Inside a purpose-built room off the main hall, I faced the circle on the floor and fed mana into it, slow as a tide. The circle answered with a gentle glow, soft as moonlight. A small girl’s form bloomed at its heart.