The Princeâs Pet[Ao3]: Diavolo x Reader
Summary: You knew that something was going to happen. You felt it deep in your chest. But nothing could have prepared you for the hand that clamped over your mouth. Branded with gold cuffs and paraded before a crowd of bidders, you catch the gaze of one powerful demon in particular. The future king has decided you belong to him, body and soul. A dark romance where love is just another word for ownership.
You tossed and turned restlessly, unable to find comfort no matter how you adjusted. Something had begun forming beneath your skin that pulled you from your sleep. Something familiar. Without thought, you reached for him, fingers brushing cool sheets. Nothing. Instead the only feeling that greeted you was an uncomfortable sensation.
The same one you had experienced on the night of the ball. The night you felt the true, searing pain the cuffs were capable of. It bloomed deeply beneath your sternum, a steady pull that made your breath hitch. Not quite pain. Not yet. Rather a gnawing discomfort that caused your hands to fly to your chest, pressing as though you could physically loosen the invisible rope that had begun to pull.
The golden cuffs answered your struggle with a low, sympathetic thrum. Almost pleased, as though they approved of your instinct to search for him.
You sat up slowly, black sheets pooling around your hips as you grasped at your chest, pleading the sensation to stop. The room felt larger without him in it. The shadows pressed on you more. The air felt thin. Every beat of your heart yanked the tug tighter, a reminder that the distance between you was no longer something your body would tolerate. You swung your legs over the edge of the bed, bare feet meeting the hard floor, and stood before you could convince yourself otherwise.
It wasnât a gentle suggestion anymore. It was a demand, coiling low in your belly, tightening with every step you took across the marble. It was as though you were lost in a trance. You followed it as mindlessly as a fish follows the current, even when it leads toward the net. Past the fireplace. Past the cushion where you had eaten the pomegranate from his hand the night before. Straight to the tall window framed in heavy crimson drapes.
You parted the fabric with trembling hands.
The distant mountains loomed ahead like an omen, dark and eternal. You knew he was out there. You pressed your palms to the cool pane and stared until your eyes burned, searching for any sign of him. A flash of wings. Golden eyes glowing in the dark. Anything.Â
The ache sharpened, and you knew it wasn't just the cuffs this time. It was deeper, crueler. The realization sank to the pit of your stomach, bitter and humiliating.
âWhere are you?â you thought, the question bleeding into something dangerously close to a plea.
Your fingers moved without permission. They found the latch, traced the ornate mechanism, and began to work it free. The soft click of the lock might as well have been a gunshot in the silence. You didn't notice. The pull had you now, mind and body. Warm, syrupy, coaxing. The window swung open on silent hinges.
Warm night air rushed in, carrying the faint metallic sweetness of the realm. It brushed across your face, lifting strands of hair from your damp temples. You leaned forward, feet right on the edge of the stone windowsill, nightgown fluttering against your thighs. Below, the city glittered like scattered jewels.Â
You imagined leaning in. Letting the cuffs pull you forward. Falling into that vast, terrible freedom even if it shattered you on the stones far below.Â
You leaned further into the open window, the constant breeze causing your hair to raise on end. The tug had become a living chain, yanking harder with every heartbeat, every shallow breath.Â
The door opened behind you with a soft click.
You didnât turn. Couldnât. Your eyes remained ahead, searching for what you already knew wasnât there. You felt your body sway, finally ready to succumb to that gnawing, incessant pull.
"Y/N," Barbatos said evenly, voice smooth as polished obsidian. "I would advise against that."
You startled so violently you nearly lost your balance, catching the frame with both hands. The tug fractured, settling into a low, resentful buzz.Â
Shock rippled through you. Had you truly been leaning out so far? One small step, one gentle sway forward, and you would have fallen. Shattered on the stones far below like the fragile human doll you were.
Your fingers gripped the frame of the window until your knuckles ached white. Would you really have jumped? The question clawed up from the pit of your stomach, bitter and horrifying. Just because he wasn't here. Just because the cuffs had decided distance was intolerable. You weren't sure if the sickness twisting inside you was fear of dying or fear of how easily you'd let the compulsion drag you to the ledge.Â
He stepped inside without hurry, silver tray balanced perfectly in one gloved hand. The scent of warm tea and something savory drifted ahead of him. Rose and vanilla, followed by something rich, spiced, and savory. Breakfast.Â
Green eyes swept over you once. At your bare feet on the windowsill, nightgown clinging to damp skin, fingers clutched on the frame. His expression settled into that familiar, unruffled calm.
"Lord Diavolo is away," he said calmly, as though commenting on the weather. "Dealing with a few of Lord Astaroth's former contacts. They've grown restless since his disgrace. It required his personal attention."
You nodded. The motion was small, jerky, barely more than a dip of your chin. Your gaze flicked to Barbatos, searching, the weight of unspoken words thick between you. Your heart began to race as those calm green eyes met yours without flinching. You already knew the truth without putting it to words.
Barbatos had seen it all. Your meeting with Solomon. Did he know what had been offered to you? Had he heard? He studied you now as though peeling back layers of your skin to examine the trembling thing beneath. You opened your mouth, but the words got stuck. What could you possibly offer that wouldn't sound like betrayal?
Before you could force them out, Barbatos spoke, voice smooth and measured, cutting through the tension like a blade.
"Lord Diavolo will be occupied for some time," he said. "In his absence, you will begin your training. We will start with the basics of Devildom script and conversational Latin. You will learn quickly, I expect."
You didn't argue. You weren't sure you had the energy left for an argument. Even if you had, something in his tone suggested that the lesson would happen whether you cooperated or not. The only difference was how much dignity you retained in the process.
You ate first, because Barbatos set the tray down with the quiet finality of someone who had already accounted for every possible objection and dismissed them all.Â
Barbatos waited, something he had become skilled in during his time serving the prince. He stood near the door with his hands folded behind his back, his expression a type of patience that suggested he could remain exactly as he was for the next several centuries without discomfort.
When the tray was empty he collected it without comment and set it aside.
"If you'll follow me, please."
Barbatos walked ahead in silence, leading you deeper through Diavoloâs private wing. Through corridors you had glimpsed before, but never dared enter. It felt endless. A labyrinth designed to remind you how small and lost you truly were. Rows of heavy doors loomed on either side, some carved with symbols that made your eyes ache if you stared too long. Staircases twisted upward or downward into shadow, promising nothing but more of this place.Â
At last, Barbatos turned down a narrower hallway lined with an extravagantly woven runner the color of dried plums and old gold. He stopped before a single door. Ebony, imposing, etched with twisting vines and blooming roses whose thorns looked sharp enough to draw blood. Without a word, he pushed it open.
The room beyond was... quieter than you expected. In comparison to the castleâs overwhelming opulence, it felt almost intentionally plain. No chandeliers. No portraits. No crimson silk. Just clean stone walls and a single tall window overlooking the inner courtyard.
You stepped inside, approaching the only thing in this room that stood out.
A desk. Made of black wood, veined with threads of a luminescent blue that pulsed faintly beneath the polish. Everything in this castle pulsed. Everything breathed. You were beginning to suspect the castle itself was alive in some way you didn't want to examine too closely.
You glanced back at Barbatos one last time.
His green eyes had narrowed, sharp and piercing. He said nothing. He didnât need to. The slight tilt of his head toward the desk was command enough. You hesitated only a moment before moving to the chair. You sat immediately, spine straight, hands folded in your lap so as to not invite correction.
Barbatos placed a heavy book before you without ceremony. The cover was bound in something that wasn't quite leather, dark and faintly warm beneath your fingertips. No title on the spine. No author. Just a single symbol on the front in gold, something that coiled and shifted the moment you tried to look directly at it, like a word written in smoke.
"Devildom script," Barbatos said, settling into the chair across from you with the unhurried grace of someone who had taught this very subject thousands of times. "You will begin by learning to read it before you attempt to write it. The two are their own distinct skills. Writing comes with consequences for the untrained hand."
You looked up. "Consequences?"
His expression remained perfectly serene. "Open the book, please."
The pages were not white. They were a deep, muddy grey, and the script printed across them was unlike anything you had ever seen. It didn't sit still. The letters, if they could be called that, coiled and writhed at the edges like living things that refused to be pinned to the page. Every time you tried to focus on a single character it seemed to slide just out of reach, retreating behind the one beside it. Your eyes chased the lines instinctively, like chasing movement in your peripheral vision. Within moments a dull, spreading ache had begun to bloom behind your temples.
Barbatos folded his hands on the desk. "Devildom script is not a human language. It was not designed for human eyes, human minds, or human comprehension. What you are seeing is the script attempting to resist you." A pause. "It does that with everyone, at first. The headache will be manageable if you do not try to force it."
You pressed two fingers to the bridge of your nose. The ache had already deepened, a low throb that pulsed in time with the golden cuffs at your wrists. "And if I do try to force it?"
Barbatos's eyes drifted to the window, then back. Unhurried. Unreadable. "Then it becomes considerably less manageable."
You looked back at the page.
The characters curled and shimmered in the low firelight, casting faint halos of color at their edges. If you unfocused your eyes slightly, the way you might when staring at one of those hidden image puzzles from your childhood, the shapes almost became something coherent. Almost. The moment you tried to focus back to them, they flickered and dissolved again, leaving behind only the nauseating vertigo of something your mind couldn't quite catch.
It was like trying to read underwater.
"Begin with the first line," Barbatos said. "Do not attempt to translate. Simply observe."
You watched the letters intently.
The tug behind your sternum pulled. The characters swam. The headache built in slow increments, pressing against the backs of your eyes. Overstimulating didnât scratch the surface of what you were experiencing. You breathed through it and said nothing.Â
An hour bled into more. The tug grew sharper, more demanding, a constant low pull that made concentration fracture. Time moved strangely in the castle on the best of days. Today, without Diavolo's presence to anchor it, the hours felt as though they were stretching and compressing without warning. You sat with the book and the slowly worsening headache while Barbatos moved quietly around the edges of the room, occasionally setting a fresh cup of tea at your elbow without being asked.
The tea helped. Slightly. It tasted of honey and something almost medicinal, warming your throat in a way that briefly numbed the worst of the throb behind your eyes. You drank it without asking what was in it. You had stopped asking those questions.
"The third character in the second row," Barbatos said from somewhere behind you, his voice as composed as ever. "You keep returning to it. What do you notice?"
You squinted at the offending shape. It was longer than the others, with a tail that curved back on itself in a tight spiral. When you looked at it directly it seemed to contract, curling inward like something flinching. "It⊠It looks like it's trying to hide," you said. "Like it doesn't want to be read."
"Perceptive." He appeared at your shoulder, close enough that you felt his cool, radiating presence. He tapped the character once with one gloved finger. "This is the foundational mark for resistance. It appears throughout the script as a warning to those who understand it. A signal that what follows carries consequence."
You stared at it. "A warning."
His voice held nothing. No inflection. No hidden smile. You looked up at his face anyway, searching for the confrontation you had been bracing for since breakfast. But his expression only offered that flawless, professional calm. Green eyes on the page. Not on you.
"Does it appear often?" you asked, keeping your voice carefully even.
"More often than most would initially expect," he said, stepping back toward his chair. "Though with time, you will learn to recognize it quickly. The script is not trying to deceive you. It is simply reminding you that some paths, once chosen, carry weight that cannot easily be undone."
You said nothing. Was he implying something?
Next came Latin, which was much easier. Embarrassingly easier, given how you had struggled with the first subject.
Barbatos handed you a different text. This time, its letters were stationary, fixed obediently where they had been printed. Classical Latin. Dense, formal, structured. The grammar was rigid, but your mind latched onto it as something that was finally within your human understanding. Here was something that behaved. Something that stayed where it was put.
"Translate," Barbatos instructed, pointing to the first passage. He placed a translation dictionary next to you. You flipped between the pages, searching for the correct words and scribbling them down until a full sentence had formed.
You read it slowly, keeping your voice even. "The one who serves willingly receives what the one who flees will never find."
Barbatos regarded you for a moment. "Good," he said simply. "Continue."
The next passage. To remain is to be kept. To run is to be lost. The demon who claims does not forget what was promised beneath his roof.
Your jaw tightened almost imperceptibly. You translated it without any comments, the words biting against your tongue. Barbatos made a small, approving sound and turned the page.
It went on like that. Passage after passage, each one neutral on its surface. Yet each one landed somewhere specific, somewhere tender and bruised beneath your ribs. You couldn't decide whether he had selected these texts deliberately or whether you were reading too far between the lines. The uncertainty was worse than an accusation would have been. With an accusation you could at least defend yourself. Against implication? You had no footing at all.
By the fourth passage the tug behind your sternum had sharpened again, amplified by the creeping anxiety and the gnawing absence of him. You pressed your palm flat against your chest beneath the desk where Barbatos couldn't see, willing it to ease, and kept reading.
What belongs to the crown cannot be surrendered. What is marked cannot be unmarked. What has been vowed endures beyond the vow-maker's desire to forget it.
You translated it. He was doing this on purpose.
Barbatos said nothing this time. He only turned the page.
The afternoon bled into evening. The fire was stoked twice by invisible hands. A tray appeared bearing small round pies with braided crust and a glass of something purple that smelled of peaches and spice. You ate mechanically, barely tasting, while Barbatos moved through the lesson with the unhurried patience of someone who had centuries to spare and intended to use every one of them.
You were good at this, you couldn't deny it. For some reason, Latin settled into your mind with ease. Barbatos noted your talent with brief praise that made your chest flutter lightly. It felt wrong. Being praised for learning the language of your captivity felt like being complimented on the elegance of your own cage.
But you kept going. Because stopping might invite conversation. Because concentration, however painful, was better than silence.Â
Solomon's face bled into your mind whenever you let your guard down. That knowing, careful smile. âThat window is small, and it closes faster than you'd believe.â The words lived inside you now, burying themselves deeper every time you tried to ignore them. Last night's vow pressed against the memory like a rebuttal, irrevocable and sweet with pomegranate. âI vow it. I won't leave. I'll stay with you. Here. Forever.â
Had any part of you meant it?
The cuffs pulsed, warm. As if they had heard the question and were offering their own quiet answer.
You pressed your fingernails into your palm beneath the desk and translated the next passage.
The candles had burned low by the time Barbatos set the texts aside.
He didn't announce the end of the lesson. He simply closed both books and rose, moving to stand near the fireplace. The flames painted his face in an amber glow, his eyes narrowed ahead. For a long moment he stood with his back to you, gloved hands folded behind him, watching the embers with an expression you couldn't read from this angle.
You waited. The tug coiled. The room breathed.
His expression was the same. That impeccable composure that had not cracked once throughout the day. But his eyes were different.
You had never seen them like this. Still green, still calm. But the emotion behind them now was not indifferent. It was dark. It was patient. The kind of quiet that came before the storm. Not anger. Something slower than anger, more permanent.
He looked at you for a long moment before he spoke.
"You are frightened," he said. Not a question.
Your throat tightened, and you said nothing.
"Not of him," Barbatos continued, voice dropping to something more deliberate, enunciating every word. "You have grown, if not accustomed to him, then at least familiar. What frightens you now is something else entirely."
The fire popped softly. A log shifted and resettled.
"You are frightened," he said, "of becoming like them."
The breath left your body.
You didn't ask who he meant. You didn't need to. The image rose without permission. Loralai's bright face. The brunette's freckled, radiant smile. The blonde man's dreamy, half-lidded eyes. Their golden cuffs catching the light like they were proud of what they had become. You swallowed hard, but the tightness in your throat had already become something more, something that stung behind your eyes and made your jaw ache with the effort of holding it back.
Your eyes burned as he stared at you, almost expectantly.
"I⊠I watched them," you said after a brief pause, your voice smaller than you intended. Rougher. "In that room. They were happy." The word felt wrong in your mouth, like trying to describe a color you had never seen with your own eyes. "Or⊠at least they looked happy. They talked about their demons like they were sacred to them. Like they had chosen this."Â
You pressed your lips together, then forced yourself to continue, your voice no more than a faint whisper. "I couldnât stop thinking that they probably sat where I'm sitting. Fought what I'm fighting. And something happened, and then they just⊠stopped. Stopped being themselves. Stopped wanting the things they'd wanted before."
A tear slid free. You wiped it away with the back of your hand, furious at it.
"I don't know how much of me is still me," you said. The admission felt too vulnerable, too honest. "The cuffs make me feel things I haven't chosen to feel. He makes me feel things I haven't chosen to feel. And I made a vow last night that I-" You stopped. Drew a careful, shaking breath. "I don't know what I meant when I made it. I don't know if I meant it because I wanted to, or because everything in me has been trained to obey and I can't tell the difference anymore."
The silence that followed was deafening.
Barbatos didnât move. He stood by the fireplace with that same careful stillness, watching you with those dark, patient eyes. When he finally spoke, his voice had not changed in tone or volume. It remained exactly as it had been all day. And somehow that was worse than any raised voice could have been.
"I will not insult you," he said quietly, ignoring your tears, "by pretending I don't know the conversation that had followed your meeting with the other humans."
Your blood went cold as your eyes snapped up to meet his.Â
"Nor will I pretend," he continued, "that I am unaware of what was offered to you, or that I cannot see the internal conflict you are struggling with." He tilted his head. "I am, as you may have gathered, very difficult to deceive."
You couldn't speak. The cuffs had gone still against your skin, as though they too were waiting. Even the pull behind your chest had dulled. It was as though everything in the world had paused to listen. To lean in.
"What I will tell you," Barbatos said, each word measured and unhurried, "is this."
He took one step toward you. Just one. The firelight shifted with him, throwing his shadow long and dark across the marble floor between you.
"I do not issue threats. They are, in my experience, inefficient. What I offer instead is clarity. You are frightened of losing yourself. That fear is not unreasonable. In fact, it is the most lucid thing about you at the moment." His voice dropped lower, quieter. "Hold onto it carefully."
He let the words settle. Let you feel the full weight of them pressing down through the silence. He continued.
"But understand that the path you are considering is not one that will save you. What awaits a human who attempts to leave, who breaks a vow made beneath this roof, who accepts assistance from those who hold no true claim over them-"Â
Another pause. The pause of someone selecting the exact tool for a delicate task. "It will be unlike anything you have yet experienced here. Not the cuffs. Not the corrections you have already endured. What occurs when something belonging to the future king is taken from him goes beyond punishment as you currently understand the concept."
He said it without raising his voice. Without a single flicker of cruelty crossing his expression. Simply as a demon who saw the edge of a cliff and, out of something that might generously be called mercy, called out to someone standing unknowingly at its threshold.
"I am not telling you this to frighten you," he said. "I am telling you because you asked, in your own way, the right question. You want to know how much of you remains." His gaze didn't waver. "The answer is enough. Enough to be frightened. Enough to resist. Enough to ask." A final, measured pause. "Whether that remains true depends entirely on the choices you make from this point forward."
He stepped back. One precise, final step, returning the space between you to something appropriate. His hands folded neatly behind his back.
"The lesson has concluded for today," he said, his voice returning to its usual neutrality as though the past few minutes had been nothing more than a footnote. "You will rest, and Lord Diavolo will return by morning. I will seal the window in his chamber so as to not have a repeat of the incident from this morning."
The word landed heavy in your chest. You would have to endure this damned tugging until morning?
You didn't move immediately.
The chair held you a moment longer than it should have, your hands still flat against your thighs. Barbatos's words had settled into you the way cold settles into stone, filling every small crack until the cold was ubiquitous.
You had experienced quite a lot by now. You understood clearly what the cuffs could do when pushed. You had felt your own voice shred itself raw in your throat while the room watched. You had felt the searing current move through you mercilessly, folding you in half on the floor of a chamber full of demons who observed your suffering with pleasure.
That had been correction for a single evening's disobedience.
You stood on shaky legs and followed Barbatos into the corridor. He walked ahead of you at that same unhurried pace, polished shoes clicking softly against the stone in perfect rhythm.Â
You thought about what lay beyond the warning Barbatos had given you. Not the specifics, he hadn't given you specifics, and you understood why. Your mind, left to its own devices, constructed its own. It had become very good at that in recent weeks. It filled the silence with teeth.
You had seen what Diavolo did when Astaroth laid a hand on you uninvited. You had felt the air go dark and metallic in the carriage, had watched the shadows in the room press closer at his mood. And that had been for a touch. A brief, unwanted touch in a public corridor.
You thought about what the word taken meant in a different context entirely. Not borrowed. Not touched. Gone.
The memory of Solomon flashed into your mind. The way he had looked at you with sympathy and kindness, the way he had promised you a way out. You remember Barbatos's reaction. His shock and anger.
If escaping carried such a steep price, what did it mean that Solomon had offered it so readily? What did it mean that a man with seventy-two pacts and centuries of survival had smiled at you in a shadowed corner and offered freedom as though the price were simple? As though he were the one who would be paying it?
You didn't have an answer. The question simply turned in your chest alongside the tug and the cold and the cuffs' steady, patient warmth, all of them coiling together into something you couldn't yet distinguish into separate sensations.
Barbatos stopped before Diavolo's chamber.
He opened the doors and stepped aside, one gloved hand gesturing you through with that same professional, impersonal grace. You crossed the threshold. The fire in the hearth had been stoked in your absence, the room warm and amber and smelling faintly of cedar.Â
Barbatos was already pulling the doors closed.
Your voice came out before you could stop it. Small. Too small.
He paused. The gap between the doors narrowed to a sliver of corridor light and his composed, half-shadowed face.Â
"Do you think I'll end up like them?" you asked. "Like the others?"
A moment of silence spread between you long enough to hear the fire settle. Long enough to count your own heartbeats. When he finally spoke, each word was chosen with the care of someone who understood exactly what they were and were not saying.
"The others," he said, "never wanted to be anything other than what they became."
The door closed behind him with a soft, final click that echoed like a verdict.
You sat very still in the silence he left behind, turning the words over and over. It wasn't a reassurance. It wasn't a condemnation either. It was something worse than both. A statement so balanced on the edge between comfort and horror that the longer you thought about it, the less certain you became of which side you were falling toward.
The tug behind your sternum pulled, low and relentless.
You pressed your hands flat against your thighs and stared into the dying fire and did not sleep for a very long time.
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Note: I apologize for how long this update took! Finishing up both the semester and my project took a lot of effort, and I didn't have much time to write. Luckily, I'm now on summer break and can put a lot more time into my writing!
P.S. Not that anyone cares, but I got accepted into a master's program in virology :) Wish me luck.
