The apartment was still, the system interface hovering in mid-air like a silent sentinel, its soft hum threading through the silence of Ethan's small, cluttered living space.
Outside, the world continued as if nothing had happened.
Somewhere a dog barked, a car honked faintly, and the gentle buzz of electricity hummed through the walls.
But inside, Ethan sat slumped on his worn swivel chair, staring at the floating notification.
[First Summon Complete. Boss Loyalty: 100%. Suggested Commands: Assign Territory / Offer Praise / Conduct Ritual / Feed.]
He pinched the bridge of his nose and let out a long, trembling exhale. "Okay. Okay, breathe. Nothing catastrophic yet.
No screams, no fires.
Just… a nine-thousand-year-old Demon King in my backyard." He leaned back, letting the chair rock slightly. "Everything is fine."
Minutes—or maybe hours—passed.
Ethan had no real way of telling.
The apartment's clock seemed absurdly loud.
He rubbed at his temples, trying to piece together what had just occurred.
The system, the summon, the rift in reality—it all felt like a fever dream he would wake from any second.
And yet, the faint scent of ozone and the vibration in the floor told him otherwise.
Eventually, necessity won over fear.
He had to face it.
He stood slowly, his knees complaining, and tiptoed toward the sliding glass door.
The curtains rattled softly as he pulled them aside, peering out.
The creature waited.
Zar'uth the Eternal—Demon King of the Abyss, conqueror of realms, vanquisher of gods—stood perfectly still in the middle of the yard.
His black flames were dimmed but still curled lazily around his horns.
His eyes, red as molten rubies, watched Ethan's every move.
They held no hint of malice, only a patient reverence, as if he had been waiting for this exact moment for centuries.
"Right. Okay. Approach slowly," Ethan muttered, taking one tentative step onto the balcony.
The wood creaked, and Zar'uth shifted slightly, one clawed foot scraping the dirt in acknowledgment.
"Uh… hi?" Ethan's voice cracked.
He cleared his throat. "I mean… Hello. You're… here."
The Demon King tilted his head, the movement impossibly fluid, like molten shadows poured into the shape of a king.
His voice came, deep and resonant, vibrating against Ethan's chest as though the very air were made of sound.
"I am Zar'uth the Eternal. First of my name, SSS-Rank Demon King, Vanquisher of Ten Thousand Realms, Lord of the Infernal Abyss, Breaker of Seals, Wielder of the Voidfire, and Conqueror of the Ninth Hell."
Ethan's brain just… stopped. "Okay. That's… a lot. Right." He tried to rub his face but froze, his hand trembling. "Seriously, how do you even remember all of that?"
"I do not forget the names of those who kneel before me or the annals of my conquest," Zar'uth replied calmly. "I am here because the system has bound me to you, Master. I shall serve you in any way you deem necessary. My existence is at your command."
"Right. So… any task?" Ethan asked, trying to keep his voice even. "Anything?"
"Anything." Zar'uth inclined his head, and the flames along his horns pulsed faintly, a subtle rhythm of anticipation.
Ethan's brain short-circuited.
Anything? He tried to summon some semblance of authority. "Well... okay... you can... do whatever you want. But, like… don't destroy the house."
The Demon King's massive, infernal visage softened slightly.
He lowered his stance, crouching to examine the yard with the meticulous attention of an ancient scholar.
A slow, almost meditative exhale of black smoke curled from his nostrils.
"My Master," Zar'uth said, his voice laced with curiosity. "This… dwelling. Is this your hidden domain? Your… sanctuary?"
Ethan blinked. "Hidden domain? Yeah, sure. This is… totally my secret fortress of power. The… uh… couch is the throne."
Zar'uth's head tilted again, closer this time, studying the glowing screen of the television. "What is this glowing white thing? A portal? A window to another realm? It hums faintly with magical energy," the Demon King murmured.
Ethan shuffled on his feet, awkward, trying to decide whether to laugh or panic. "Uh… no. That's a TV. You watch… stuff on it. Like… cooking shows, anime…"
The Demon King reached out, one clawed hand hovering just above the screen. "Fascinating. A magical artifact of mundane observation. Can it be… bound to the Abyss?"
"Uh… sure?" Ethan mumbled, retreating slightly. "Maybe… don't."
Zar'uth straightened, the smoke along his horns rising into intricate patterns as he seemed to relax.
His eyes swept across the small apartment, the stacks of dirty dishes, the unmade bed, the coffee-stained carpet.
The sheer scale of his presence contrasted with the simple mundanity of Ethan's life.
"My Master, your abode is… modest yet filled with potential. Shall I… explore further?"
Ethan hesitated. "Yeah. Fine. I… guess. Just don't destroy anything."
A small smile—or as much as a Demon King could muster—played across Zar'uth's features.
Slowly, deliberately, he moved through the apartment.
Every step was calculated, careful; his claws clicked softly against the tile. He crouched to examine the bookshelf. "So many bound tomes. Each a window to knowledge. Master, are these… your spells?"
"Nope. Uh… novels. Fiction," Ethan said, waving a hand. "Nothing magical, I promise."
Zar'uth tilted his head, reading the spines with unnerving intensity. "Ah… chronicles of mortal imagination. I… understand. Worthy of study. Truly fascinating."
He moved to the kitchen, examining the coffee maker as if it were a relic of ancient divine technology. "This device… it converts beans into a potion of… awakening?"
"Yeah. Pretty much," Ethan said, unsure how to answer. "You can drink it. Maybe. Just… don't kill me if it tastes bad."
The Demon King nodded gravely. "Of course, Master. I shall sample and report. Safety is paramount."
Ethan pinched the bridge of his nose again. "Right. Totally normal. Everything is fine."
After a few minutes, Zar'uth paused near the window, peering out at the street. "Master, I notice other humans are… moving strangely. There is… commotion. Shouts. Strange glowing lights… powers awakening. Are they… rivals? Allies?"
Ethan sighed. "Yeah. Sort of. Everyone got a system. Powers. You know… apocalyptic stuff. Weird, right? Some are strong. Some are… uh… very strong. Some are gonna try to kill us eventually. Just… FYI."
Zar'uth's eyes narrowed, a faint pulse of flame along his horns. "I see. This world… it is in peril. Yet I… wait. My duty is clear. To serve. To protect… to obey."
Ethan let out a breath he didn't realize he had been holding. "Right. Good. So… just… chill for now, okay? Don't do anything crazy."
The Demon King nodded once, then leaned closer to examine a half-eaten instant ramen cup on the counter. "Master, is this sustenance? Will it suffice for the… initial stage of my assimilation into your domain?"
"Uh… sure. I guess. Just… don't spill it on the floor." Ethan muttered. "Also… don't blow up the apartment. That would be bad."
Zar'uth's massive frame shifted, smoke curling from his horns in delicate, hypnotic patterns. "Very well. My Master's command is absolute."
For a long moment, the apartment was quiet again.
The interface hummed softly.
Outside, life continued with oblivious regularity: the dog barked somewhere, a car honked, a siren wailed in the distance. Inside, a college dropout stared at a kneeling, obedient SSS-Rank Demon King exploring his kitchen like a curious tourist.
"Well," Ethan muttered finally, sinking into his chair, "this is happening. And I… guess I… deal with it."
The interface blinked softly, tiny words scrolling lazily across the holographic panels:
[Boss #1 Active. Loyalty Confirmed. Tasks Awaiting Master's Command.]
Ethan pinched his temples and let out a sigh so long it seemed to pull the room with it. "Yep. Absolutely fine.
Totally fine. Nothing could possibly go wrong."
And somewhere in the back of his mind, a tiny, reluctant spark of schemer logic flickered. Maybe… just maybe… there was a way to make this work.