Diabolically Yours | part III (vessel!demon x reader)
Summary: Emma just wanted a simple magical boost to win a writing contest, not a snarky and handsome demon bound to her soul. But after summoning the wrong hellspawn, she ends up stuck with Vessel: a sarcastic, shirtless chaos entity who won’t stop flirting or stealing her snacks. Now they’re magically tethered, emotionally entangled, and dangerously close to something much scarier than a pact gone wrong... feelings.
TW: Contains supernatural shenanigans, mutual pining, steamy tension, and one annoyingly hot demon. Read with care (and maybe holy water on the finals part).
💖 masterlist
Part I | Part II | Part III
Part III: Brainstorming with a Hellspawn
"No romances. There are too many of those in the world already. You need something more... unique," Vessel said, standing in the middle of the living room.
It had been hours since they’d left the library, and Emma was on the couch with her laptop balanced on her knees, fingers hovering hesitantly over the keyboard. The damn cursor blinked at a merciless pace, as if mocking her inability to come up with an idea that was... good. Vessel stood in front of her, hands on his hips, watching.
"You need something more... visceral. A story that bites. That scratches. That doesn’t ask for permission before climbing into the reader’s head," he went on, now pacing in circles around the couch like a literary coach possessed by Nietzsche and espresso.
Emma rubbed her temples.
"I just want to turn in the assignment and pass. I don’t need to become Sylvia Plath."
"You don’t need to become anyone. You need to become you. Unlocked version, you know? Blood in the eyes, nothing to lose."
She stared at the screen. The first sentence she’d written: "Once upon a time, in a forgotten village…" Now felt like a personal insult.
"I hate all of this."
"Excellent start. Hate is a great fuel."
Emma huffed.
"Can you stop parading around like a Broadway villain and just give me a decent suggestion?"
Vessel stopped. Turned to her slowly, like he’d just had a profane epiphany.
"You should write about us."
She choked.
"What?"
"Exactly. A lonely human who accidentally summons a demon. Sounds like an irresistible metaphor for youth, frustration, and shattered expectations. Throw in a little chaos, a dash of sarcasm... done. Autofiction with an infernal pact."
"That’s ridiculous."
"That’s genius. It’ll confuse your professors, intrigue your classmates, and get you a great grade. No one will know where the metaphor ends and the breakdown begins. That’s art."
Emma stayed quiet for a few seconds. Then, very slowly, she began to type:
"She didn’t mean to summon anything. She just wanted to finish a short story. But sometimes, the universe confuses intentions with declarations. And then he appears. With sarcasm in his eyes and questionable taste in reality shows."
Vessel read over her shoulder, a slow smile spreading across his face.
"Now that has soul."
"That has you, which is basically the opposite of soul."
"Touché."
Vessel leaned back on the arm of the sofa, watching Emma type with the kind of concentration that only appears under the threat of a deadline or demonic possession. She didn’t look at him, but she felt his presence hanging in the air like a strong incense scent — annoying, yet strangely comforting. Maybe it was just a side effect of sleep deprivation.
The cursor blinked in rhythm with her heartbeat. For the first time since the semester began, Emma felt like she was writing something that truly represented her. Not a mechanical exercise of structure and technique, but a story that hurt a little to tell — and precisely for that reason, it was worth it.
"You know what’s the most ironic?" Vessel said, fiddling with his rings, distracted. "You summoned a demon trying to write about humans. And now you’re writing about a demon to try to understand yourself."
Emma stopped typing.
"And what are you quoting now? Voltaire?"
"I’m just being myself. A chaos agent with a flair for drama."
She leaned forward, cracking her fingers carefully.
"This isn’t about me. It’s just a story."
"Sure. And I’m just an inconvenient guest who steals robes and unlocks creative insecurities. Nothing symbolic."
She stared at him, eyes half-closed.
"You love sounding deep."
"I am deep. I have layers. More than onions and collective trauma."
Emma laughed, unwillingly. And she hated it a little — hated actually laughing. At him. At the situation. At herself.
Vessel smiled too, satisfied. Like someone who had just won an invisible battle.
"Can I tell you a secret?" he said, suddenly quieter, almost in a tone that sounded… human.
Emma turned to him, suspicious.
"Here we go."
"This —" he gestured around, encompassing the messy room, the stacked books, the laptop on her lap — "is way more interesting than corroding the souls of corrupt bankers. At least you listen to me. Complain, grumble, but listen."
She frowned.
"That was… kind?"
"No. That was factual. Kindness is an infernal design flaw."
"Oh. Good to know."
The silence that settled this time was less tense. Vessel lay down on the carpet like a sloppy demonic cat. Emma resumed typing, and he just followed the sound of the keys like it was music.
"So, what happens next?" he asked, almost in a whisper.
"Next?"
"In your story. The girl who summons a demon. Do they become friends? Rivals? Does she learn a lesson? Does he disappear in the end? Have you decided yet?"
Emma hesitated. Looked at the screen. Then at him.
"Not yet. I think... they’ll figure it out together."
"Hmmm. Nothing like a good character arc to keep things interesting."
"Just don’t get used to it. When I hand in this assignment, you disappear. Remember? That was the deal."
Vessel closed his eyes, a lazy smirk on his lips.
"If life were as simple as a deal..."
She ignored him. Or tried. And kept writing, even knowing — deep down — that she was no longer just writing a story. She was documenting something that had already started to happen.
"I’m hungry."
Emma didn’t look at him. "Then go devour some delivery guy’s soul, I don’t know."
"I mean real food. Burger, fries, maybe a milkshake. The kind of feast that makes the human gut cry for mercy. Come on, I’ll pay."
"You’re a demon, Vessel." She sighed, still typing.
"So? I still get paid for my work, thank you very much."
That made her stop, her mind going static.
"Demons get a salary?"
"Yes, and a very good one. In Hell, everyone gets paid. It’s a flawless infernal meritocracy. I have stocks, properties, shares in surface companies, and a Black card that works in any plane of existence. Believe me, the heaven folks envy how well we get paid — they’re always asking HR to switch plans and come down."
Emma blinked, confused.
"Wait. You’re telling me that… you’re rich?"
Vessel smiled, satisfied.
"Filthy rich. Multiplanar millionaire. I could buy a restaurant right now if I wanted. Or a fast-food chain. Or this building. Want sushi? A ten-course tasting menu? A taco truck parked outside?"
"You have a card?"
"I have an app too. Super handy."
Emma ran her hand over her face, exhausted. Too much info at once. More than she expected to be real.
"I can’t believe my accidental demon is a sugar daddy."
"Don’t abuse the term. I prefer ‘occasional cosmic provider.’"
"Okay, provider. So why haven’t you asked for anything yet?"
"Because I like when you give in first. Creates an illusion of control. But since you brought it up…"
He snapped his fingers. A digital menu floated in the air, glowing red and gold.
"Choose whatever you want. But if you try to order just a salad, I’ll swap your bath salts for a really crappy brand."
Emma laughed, because of course he’d be theatrical even in delivery.
"Fine. But dessert is my choice."
"Always."
She swiped her finger across the floating interface, trying to ignore how everything was starting to feel… normal. Ordering food with a demon. Talking about infernal payment. Laughing at jokes that, weeks ago, she would swear were clear signs of madness.
"Do you have a first-time coupon?" Emma asked, half-mocking.
"I know the chef. If you want, I can call and ask him to customize your pizza with a rune of inspiration."
"I just want carbs. No magic."
"Coward," he replied, but clicked the "confirm order" button with gusto.
Minutes later, the doorbell rang and Emma got up to get the food. They sat on the living room floor, among pillows, scattered papers, and stacked books. Emma opened the box and let out an almost religious sigh seeing the steaming pizza.
"This looks like something from a movie. Like… a ‘Midnight with the Devil,’ culinary version."
"Or ‘Eat, Pray, Summon,’" he suggested, grabbing a slice.
She laughed with her mouth full.
"Okay, confess. Do you do this for everyone who summons you?"
Vessel pretended to think, chewing with demonic dignity.
"Not always. Once in 1984, a guy tried to summon me to win a dance contest. We ended up founding a tap dance school in Oslo. Long story."
"And you became friends with him too?"
"No. He hated me. But he danced well."
Emma laughed again, and for a moment forgot about deadlines, professors, the story she needed to finish. She was just there, sharing a pizza with a being who could probably cause an eclipse with a sneeze — and yet told bad jokes and stole the stuffed crust edges.
"You’re nothing like I expected, you know?"
Vessel smiled, tilting his head.
"I’m everything you didn’t know you needed. And a bit more. Literally, I am chaos incarnate. But, let’s be honest, chaos with good taste."
Emma finished the slice and looked at him with a furrowed brow.
"I still think one day I’ll wake up and find out this was a caffeine-induced delirium."
"Maybe. Or maybe it’s the start of the best story you’ll ever write. You never know, right?"
A comfortable silence settled, the rare kind, made of crumbs and silent contemplations. Outside, the night went on indifferent, while inside, among books, pizza leftovers, and infernal sarcasm, something strange and almost beautiful began to take shape.
Vessel looked at the laptop screen, still open beside the sofa.
"After dessert… we’ll get back to your story. I’m feeling it’s almost there. Just missing a twist. Or an unexpected ending."
Emma nodded, feeling — for the first time in days — that maybe, just maybe, she wasn’t so lost after all.