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Let Me In (I May Never Leave)

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Imagine you are in a field of daisies. What are you doing in a field of daisies? Get up! Let’s say you’re not in the field anymore. Let’s say they’re not brothers anymore. That’s right, they’re not brothers, they’re just one guy, and he knows you, and he’s talking to you, but you’re in pain and you cannot understand him. What are you still doing in this field? Get out of the field!

—Crush, Richard Siken



As a hunter, Crepus understands some demons far surpassed the capabilities of even the best humans. 


Which is why he’s not ashamed when he brings out an old family tome, yellowed pages crinkling with each turn, the demon he’d planned to contract decided weeks before. He thinks of it as a birthday gift for his son, albeit a rather unconventional one—but would serve Diluc well into his adulthood. He is old, after all, his aching bones a reminder that he cannot be there for his only son forever.


He sets the tome, a bag of his supplies, and lamp down on a nearby table, the howling wind and light rain outside beckoning the start of the storm. He’d found the abandoned shack deep in the forest sometime back, surfaces covered with a thin layer of dust, and traces of nature reclaiming its spot with vines and weeds growing on the inside. It will serve its purpose today, and later he will burn it to cover his tracks. 


Crepus hopes the nanny managed to usher Diluc to bed tonight, he doubts he’ll be home anytime soon.


First, the candles. 


Six in total, equally spaced apart to outline the gate. Next, the actual summoning circle, drawn in chalk. Crepus is careful with the lettering and shapes, mindful of the fact he will have to start all over again if he does not get it right, one wrong word could unintentionally invite something else into the space he’s created. Finally, the wards, drawn on the outside of the candles, meant to keep the creature in the shack, and hopefully give Crepus some time to bargain a deal.


The thunder starts as he finishes the final touches of the ritual circle, and he goes over it thrice over to make sure there are no mistakes. Only once everything is in place does Crepus bring out the knife, slices deep along his palm and allows the rivulets to drip onto the floor, soaking into the white chalk as he begins chanting.


He is dismayed when the first few minutes yield nothing, the rain outside turning into a torrential downpour as the night continues. He thinks the cold he feels is due to the weather, but the chill progresses—his breath coming out as a fog before he notices the abnormal drop in temperature. The candles are still too, the flames do not shift as they should in a room with a breeze, and the wax does not melt.


A loud crack follows an abrupt strike of lightning, and the candles immediately extinguish, drenching the room in an eerie dark as Crepus stops chanting. 


“How peculiar,” a soft, sibilant voice begins to speak, echoing in the space around them. “—for a hunter to seek a demon when you reek of your slaughters.”


He winces, careful to keep his eyes down. “I apologize.”


A giggle, like a child's, “no need for that, hunter. Though you should be glad I’m interested in listening to your offer.”


He knows better than anyone the dangers of summoning, if his call had not landed on his intended demon something else would have invited itself into the space—and there’s no way to tell what would provoke the creature. Demons in general, from what he understood, did not like his ‘smell’. Accumulated from the encounters that usually ended in their death, a method the creatures used to warn each other that a human was dangerous.


“I have a son,” Crepus begins, honestly. There is no use being earnest with a demon, but the least he could do is reveal his motivations for it to judge. “My sole heir, young, and already showing so much promise. I… do not want him dying before me.”


Deafening laughter, raucous, a cacophony of sounds and different voices. “You seek a guardian angel, hunter. What are you doing, asking for help from a demon?” A breath against the shell of his ear, a harsh whisper, “I could make a deal with you and eat that precious boy of yours just as easily.”


“I refuse to rely on the divine if they allowed my wife to die,” he replies. 


“Is that so.” The creature hums, the fog against his ear gone. “Let’s hear it then, what do you have to offer?”


“My soul,” Crepes immediately answers, “—upon my natural death. For my son to have a companion he may rely on, when his father is no longer there.”


“Touching,” the demon drawls, clearly uninterested. “A single soul is lacking in a deal that is meant to last a human lifetime, though I suppose it makes up for it in… ailing my boredom. Imagine that. A demon, aiding a future demon hunter.” A chuckle, dark and rich. “I suppose we have a deal, hunter.”


“What is your name?”


The shadows swarm, coalescing into the singular spot where he’d allowed his blood to drop. From the darkness, Crepus is surprised when a boy steps out. Dressed as any noble child would, with an idle smile on a face as young as Diluc’s. Twilight blue eyes are unnaturally bright as the demon speaks its chosen name for him to bind.





The thunderstorm rages.


When he hears the sound of harried footsteps, Diluc is quick to set his book aside, knowing it's the servants going to greet his father at the front door. Crepus is drenched, the carpet damp where he stands, accepting a towel gratefully as the maids tend to his wet overcoat.


He calls, “father—” and then abruptly stops, noticing the smaller figure huddled next to him.


“Diluc.” His father does not immediately go to reprimand him for staying up late. Instead the older man gently pushes the mysterious child to the front, the hood falling away to reveal a boy with startlingly clear crystal eyes. 


“This is Kaeya, he will be staying with us… for the foreseeable future.”


And Kaeya looks nervous, glancing wearily at the servants surrounding them. Diluc immediately feels sorry for the boy. He knows what his father does, and sometimes the jobs ended with casualties—he’s no stranger to their mansion housing ‘guests’. Though it is the first time he’s met someone as young as him, and judging from his fathers tone, he doubts Kaeya will be leaving anytime soon.


Diluc tentatively reaches forward, gently holding much colder hands in his. He should probably help prepare a warm bath. “It’s nice to meet you.”


Kaeya smiles, hesitant and shy.



“Is the water okay?”


He nods, sinking deeper beneath the bubbles, watching Diluc turn away for a moment to grab a bottle from a nearby shelf. He’d shied away from the touch of the maids, clinging to his new ward and delighted to find the young Ragnvindr receptive to his presence. He’d seen the obvious discomfort in Crepus’s eyes, and wondered how long it would take before the old man started asking for the contract to be rescinded. 


It would be easy to reach out now, grip that tiny throat around his fingers and make a meal out of every single person in the mansion.


Diluc turns back, a purple bottle in hand and a grin on his face, “Lavender is my favourite, I hope you’ll be okay with it. Can you close your eyes?”


Kaeya does as he’s told, quiet as he listens to the soft humming, small fingers working the lather onto his head. He’s seen noble children of this era, most of them spoilt and fussy things, yet Diluc is patient—even willing to do a servant's job because of the pity he felt. 


Such a sweet boy.



Wherever Diluc went, Kaeya could usually be found a few steps away.


Not that this new dynamic changed much. The people of the manor find their young master’s new friend cute. A little quiet, perhaps a touch too observant, but that was to be expected after what he'd been through. Diluc remains attentive, regularly stopping between his training just to make sure Kaeya wasn’t too bored waiting for him to finish. 


For the first few days a doctor had been a staple presence around the residence, mostly there to offer suggestions on what a traumatized child could consume. Nothing too heavy, but nutritious meals, followed with plenty of fruit with occasional pieces of candy. Diluc would usually be the one to help bring the meals up, staying with his new friend until his tray was cleared, repeating the cycle until the boy was well enough to eat at the family table.


“Can Kaeya sit in on lessons and start training?”


“I don’t see why not,” Crepus responds after a beat, “I will inform your tutors of the changes.”



And when there are storms, he pretends.


Quietly slips into the bedroom one door away, finds his way under the cover of warm sheets and into welcoming arms that gently embrace his lightly trembling body. There is a hand carding through his hair, and a voice against his ear to comfort him. He plays the role of a terrified child well, but seeping the warmth from Diluc, earning the boy’s trust, is a reward all in itself.


The maids in the morning coo when they find their bodies curled against each other, whispering to one another how well they got along, like brothers.


Who was Kaeya to deny words cementing his position within the family?



“I don’t think I’m very good at this.”


He watches Kaeya loosen his grip on the practice sword, flopping back onto the grass with a groan where he’d been knocked by Diluc’s swing. He stifles a laugh, moving over and holding his hand out.


“Whining isn’t going to get you anywhere, come on.”


Kaeya grumbles, but allows himself to get hoisted up. Diluc helps him fix his posture, showing where to grip the hilt of the sword even though the boy clearly doesn’t enjoy the training. 


“We can stop when you learn to defend yourself.”



Diluc is fourteen when he decides to be rebellious and go off into the dark forest alone.


Kaeya follows, only because he is bound to protect Diluc even if the boy doesn’t know it—and the forest is rife with activity, especially during the night of a full moon.


Only a family of huntsmen would think it apt to build a mansion in an area known for its dangerous beasts. Really, what were the first Ragnvindrs even thinking?


He can’t imagine what goes through a teenager's mind either, though it’s probably just him working through his reckless phase by trying to prove something. They’d long passed the boundary of the family wards, out of the safety zone and into the wild. It wouldn’t be long before someone notices the young master out of bed so Kaeya is just holding out until then.


“Diluc, can we just go back—”


“No,” he hisses, “the other hunters won’t treat me seriously until I bring back my first k—”


Then, howling starts around them.


Immediately they are cornered, of course they would be, they are foreign smells to the locals of the forest and it was only a matter of time before something hunted them down. Diluc is quick to draw his sword, and Kaeya does the same, but two teenage boys are no match for grown werewolves no matter how gifted they may be.


Still, it would be a good lesson for Diluc.


Kaeya drops his guard to an oncoming attack, screeches when sharp claws go for his eye, digging deep into the socket. And it must make quite a traumatizing sight for his brother, who screams his name as he clutches the bleeding organ. Honestly he only wants to scare his ward, can’t have Diluc thinking the world is all roses. 


And what better way than a permanent injury to serve as that reminder?


He thinks that will be that, and Diluc will be forced to admit defeat. Kaeya will knock his rambunctious brother out and kill the pesky mutts and bring them back, adjusting everyone’s memory along the way to make it seem like they escaped safely. At least, that is the plan. 


What he does not anticipate is the burst of flames.


A glorious inferno of reds and oranges, the roar of the phoenix’s blessing deafening as the fire scorches everything in its path. Kaeya absolutely was not expecting to learn something new about his charge tonight. The phoenix represented many things, rebirth, immortality, solitude—but most of all it was a holy creature.


An angel had obviously gotten frisky with someone in the Ragnvindr bloodline.


The fire however, is untrained, far too raw to be used in combat—at least for now. Kaeya urges him to sleep then, catching Diluc’s slack body in his arms, allowing his frost to eat the hearts of the few remaining werewolves standing.


The butler will find them later, at the edge of the household wards, passed out and exhausted.



Diluc keeps the memory of his own awakening, as well as Kaeya’s fabricated one.


Two magic users in one household will be news, but all eyes will be on the heir and pride of the family just as it should be. 



“I’m sorry.” 


The grief eats at him seeing the eyepatch, a normal injury may have been easily healed but a werewolves claw is something not even the most advanced of spells could repair.


One clear crystal eye, gone , all because he couldn’t set aside his stupid pride.


Kaeya smiles, and Diluc feels like he doesn’t deserve the forgiveness—he’d rather Kaeya angry, spitting curses at him, not a soft voice telling him,


“It’s okay.”



“You must be proud,” a baron mentions to him in the middle of Diluc’s birthday party, but Crepus cannot for the life of him remember the man’s name. “To have such gifted boys for sons. I hear your eldest was scouted by the royal family? Knighthood would be such an honour.”


Diluc is the center of attention for tonight, politely engaged in conversation with the noble swarmed around him. A talented hunter with great expectations once he comes of age, and who will always be Crepus’ pride and joy no matter what he chose to do.


“And your second, goodness, a prodigious mage in the making I’m told.”


Kaeya is his careful shadow, silver tongued and effortlessly charming. Who’d chosen instead to focus his talents on the magic academy, showing promise as a caster. 


“Fear not hunter,” Kaeya had said to him one night, an unnatural glint in his eyes reminding Crepus what he was addressing. “You only wanted a companion for your son right? I have no intention of ever outshining my brother.” 


“I hear they’re unattached too,” the man coughs, “my nieces are lovely girls and—”


Crepus bows, careful to excuse himself out of the conversation, “if you’ll excuse me, baron.” 



“That is a ridiculous request. Do you realize what you’re asking from me?”


Kaeya shrugs. “You forget, our deal entailed only you and Diluc. Everyone else in this household is not on that list.”


Crepus frowns, the tight lines on his face telling of his thoughts, but relents. “Fine. I will reject the betrothal letter from the royal palace.”



He thinks he’s imagining it, but Kaeya has gotten progressively… touchier with him. Not that Diluc would ever bring it up, besides they’ve been close since they were children—it shouldn’t come as a surprise. 


Except it does, because they’ll both be adults soon and he’s certain normal siblings don’t share the kind of skinship they do. Still finding Kaeya in mornings curled around him, one toned arm and muscled leg carelessly slung over his sleeping body, pulling him back against a naked chest. 


Possessive , his mind whispers. Diluc shakes the thought and goes back to sleep.



And all good things must come to an end.



Being a hunter meant more than simply going after monster bounties that popped up, it sometimes entailed escorting merchants—where a path could be littered with throngs of waiting ogres or a nest of vampires.


It is raining when the dragon attacks their convoy.


And Crepus must forget he made a deal with a demon, because he does not hesitate to throw himself in the path of the beast’s tail that comes swinging like a mace towards his son. Slamming into his body instead, crushing his ribs with the force. 


And poor Diluc, seasoned from some battles but not quite ready for a calamity of this level, having to see his father die as the dragon breaks free from the feeble chains summoned by some other caster of their group—taking to the skies once more with its great wings.


Kaeya hangs back, and people will think out of respect, allowing a son and father their last few moments together—but it’s only because he doubts he’ll be able to control the grin rapidly forming on his face. 


His first proper meal after so long, and he’s starving .



The household is quiet after Crepus’s death, and the funeral is just as dreary. 


Mourning is very much a human affair, to grieve for someone gone, an idea Kaeya thinks he used to practice as a human—a few centuries ago that is. 


Nonetheless, he wears the emotion of sorrow as they all do, careful not to break his character as the supportive second child. Issues commands to the servants when their new master refuses to leave his room, writes back to nobles that send their condolences, ponders to himself when would be a good time to have the confirmation ceremony; people will need to see who the new head of house is, after all.


But the silence has to break, he knows, Kaeya is only waiting for when .



“My drawer—” he still remembers the way his father had rasped, desperate to convey his last words even against the injury and blood loss, “—letter.”


Diluc had found the letter a full week after the funeral. It felt wrong coming into a space that had once been his father’s study—now his. 


Tucked under some account books, sealed with old wax, his name penned in elegant cursive the way his father always wrote his notes. There is no second letter for Kaeya.



My dear son, it reads. I fear I have made a grave mistake.



Is it evening by the time he finishes the letter, the sky outside caught between the dark blues of dusk and orange of the setting sun. The paper turns to black ash in his fingertips without him realizing, and the first emotion he comprehends among the turmoil of confusion that rages in his mind is… betrayal.


And then a little more clearly—hurt.





Kaeya does not defend himself when Diluc barges into his room, sword in hand, and he must have scared some maids along the way because they immediately hover at the door—faces worried even as Kaeya shoos then away with a smile and wave of his hand.


“Please leave us, close the door too. I will deal with him.”


Deal with me?” That seems to incite the boy further, pointing the tip of the dangerous blade at his throat, a bead of red forming as the servants give them privacy. “What makes you think you can deal with me, demon ?”


He spits the label like venom, and Kaeya wonders what it must feel like—to find out the person you’d grown up with all your life was a creature you’d been taught to hunt down. “I knew your old man would leave you something, he was probably waiting until you were of age to tell you.” 


The boy looks stricken, to have it confirmed must make the wound worse, “you really are a—”


Kaeya does not back away from the sword. He leans into it instead, letting the sharp metal cut into skin, drawing more blood. Diluc backs away, a moment of further weakness crossing his face, hesitation.


“—demon.” Kaeya finishes for him. “What will you do now, knowing the truth, brother? Kill me?”


Diluc doesn’t. 


He drops the sword and starts crying .


Kaeya forgets this is not another creature with centuries of existence up its sleeve, not a being that has even experienced a fraction of what life had to offer—this is a boy. A child who’d just lost the only parent in his life, and now has to deal with the crushing reality that the other pillar of stability in his life was a sham.


And Kaeya does what he’s always done best when Diluc becomes upset, he comforts.


“Oh, precious—”


Brings his arms around the boy who does not push him away, instead returning the hug, as Kaeya notes, wetting his shoulder with choked sobs and digging fingers into his back. Kaeya pets him, shushes Diluc first with a kiss on his cheek, soft lips on wet skin. Inhaling the scent of ash, firewood, burnt caramel on the tip of his tongue, the smell surrounds him as he pulls away—


“You poor thing.”


—then kisses again, this time on petal-soft lips. Swallowing Diluc’s confused whine as he slots their mouths together for something more lingering, only stopping once Diluc tilts his head away.


“What are you—”


“You’re hurt,” Kaeya says, pressing their cheeks together, a hot breath on his ear and he delights feeling Diluc tremble against him. “I can make you forget, just for a bit.”


The hesitation returns to his eyes, lovely mind undoubtedly overthinking it all. Kaeya’s lips go back to ghosting over Diluc’s, sharing a heated breath between them. “Let me do all the work,” he murmurs, low and comfortingly, stoking the fire ever so gently, “please?” 


Diluc meets his gaze, then immediately looks away, the flush on his cheeks darkening. “...Okay.”


Kaeya guides their bodies towards the bed, pressing their lips back together, parting only as Diluc falls back onto the soft sheets. Fingers reach behind his neck, going upwards and fisting into dark locks of red, pulling his head back. Diluc gasps, then tumbles into a moan as Kaeya licks the pale expanse of his offered neck. Nipping along unblemished skin, leaving red bites as he trails lower, free hand undoing the lace of the frill top allowing him more canvas to mark. 


Once satisfied he goes back up, kissing the shuddering hunter once more, grinding their arousals together and licking parted lips as Diluc whimpers. Then shivers as Kaeya places both his hands under his shirt, cold hands on hips, moving upwards to remove the first article of clothing between them. Diluc is shy as a virgin bride, hands immediately covering his chest, the action making Kaeya chuckle. 


“We’ve spent countless nights together already,” he muses, gently moving Diluc's hands aside. “Though I admit it’s cute that you feel the need to hide now.”


“That was—” Diluc starts, then yelps in surprise as Kaeya dips down, licking on a pink nipple, “—different.”


He makes a noncommittal sound of agreement, suckling on the nub until it hardens, alternating his attention between the two and relishing in the sounds of pleasure escaping Diluc. From a rosy pink to red and bruised like fruit, twitching and sensitive like its owner. Kaeya moves lower, undoing Diluc’s pants even as the hunter keeps his eyes shut, taking a sharp inhale of breath as Kaeya runs a hand along his arousal. Fingers curling loosely around the shaft, idly stroking up and down as Diluc whines. Cute, he thinks.


Kaeya drags his tongue across the leaking head, tasting pre, then pops the rest of the length between his lips and swallows.


Diluc moans, a sound long and drawn, shaky hands coming to grip navy blue locks between his fingers as Kaeya continues his assault. Dipping his head until fine red hairs tickle his nose, and pulling up leaving only the tip enveloped by his mouth, repeating the cycle. For Diluc—whom Kaeya had ensured never even get as far as kissing a stranger—it’s a whole new experience that makes his body twist; hips held down from moving too much as Kaeya sucked. 


He comes with a cry, gripping Kaeya’s hair harder and bucking up into his mouth. Kaeya hums as he suckles the shaft clean, the vibrations going straight to the sensitive cock as it slowly goes soft. Diluc is a wonderful sight, pupils blown and limbs spasming as Kaeya pulls his pants off the rest of the way, and starts stripping himself.


The hunter must realize they’re not done, because his eyes go wide staring at the demon’s cock, hard and curved.


“Do I—?” he starts, looking a little unsure as Kaeya stifles a laugh behind his hand.


“I promised, didn’t I? I’ll do all the work, you just have to lie there and let me take care of you.”


He meekly does so, watching Kaeya reach for the bedside drawer, bringing out the bottle of scented oil typically applied before bed to aid sleep. He coats a hand in the liquid, then drops the rest on Diluc’s belly, messily dripping onto the covers beneath them. 


Kaeya pulls one of Diluc’s legs over his shoulder, and the boy looks so exposed this way—puckered hole twitching, unsure of what's to come. 


“Breathe,” he soothes, gently rubbing one digit over the furled muscle. “I’ve never hurt you, have I?”


Those words seem to calm him, enough for Kaeya to push one finger in and begin stroking his inner walls.


“W—wait it’s strange—” Diluc whimpers, whining when he feels a second finger join the first. Opening him up, looking for something. His back arches, gasping as Kaeya triumphantly finds the spot, pads of his oiled fingers rubbing over the sensitive bundle of nerves that sends pleasure tingling down Diluc’s spine. Toes curling in response, and legs falling further apart in invitation, his limp cock twitches in renewed interest. 


Kaeya continues to coax noises out of him, a third finger added to the mix and further stretching his hole for what was to come. Diluc whines feeling his cock jerked by Kaeya's other hand, his own gripping the sheets behind him and not sure whether to thrust his hips up or bear his ass down on the intrusion. Once he’s satisfied, Kaeya removes his fingers, shushing Diluc as the boy makes a sound of hurt confusion at being denied.


“Almost, precious.”


He angles the head of his cock, pushing it past the ring of muscles relaxed from ample preparation. But it must still be too much for Diluc all at once; his body jolts against Kaeya’s, tears forming along the corners of his eyes as the demon continues to push in—sheathing himself completely into his ward's willing body. 


Kaeya groans, two hands holding pale hips, pulling back and thrusting. Pressing harder where their waists are joined, coarse pubic hair rubbing against sensitive bare flesh.


Diluc sobs, jerking as Kaeya leisurely slips his cock out. The pace borders on cruel as every push back in is dragged across that same spot that makes his whole body tense, greedy hole clenching around the shaft. His own cock between his legs is drooling messily, painfully hard once more. 


“N—no—” he twists away with a shudder, biting his lips. 


“No?” Kaeya murmurs back, hiding a smile as he rolls his hips with the movement. 


“M-more,” Diluc gasps, breathless, lashes dark with clinging tears.


Kaeya obliges.


He cries as the pace turns brutal, savage as the tight grip around his waist that will probably leave bruises once they’re done. But the moment is filled with only the two of them now, the sound of hips slapping against each other, a thick cock fucking Diluc open, his mouth slack and jumbled words of desperation filling the space between them as Kaeya continued to bottom out. Relentless in his promised pace, hitting the same spot that turned the hunter’s mind to white noise, he pushed him closer and closer towards the edge of something overwhelming.


Diluc whimpers as he comes the second time, body shuddering with the force of the orgasm that rips through him, spilling messily over his own chest.


“There we go,” Kaeya croons, low and lovingly as he continues to fuck into Diluc’s shaking body. “I’ll take care of you.”


The hunter dissolves into a weak moan, going limp as Kaeya joins him over the edge with a satisfied groan, filling his body with unfamiliar warmth.


And for that brief slow and syrupy moment in the afterglow, exhausted but content, Diluc does forget everything.



When he is officially instated as the Ragnvindr head, Kaeya is there, right by his side. 


Charming the nobles with empty promises, most of them Diluc wants nothing to do with, and even manages to keep the women off his brother's arm throughout the party with equally empty flattery. He’s careful to position himself right next to Diluc, not close enough that it would bring up any unwanted questions, but just enough for others to understand that Kaeya wasn’t intending to leave his side anytime soon.


He would need the support from his brother, the nobles think. He lost one family member, he doesn’t need to lose another.


And at night, when the lights are out and the servants know to keep away from their quarters, Kaeya fucks him to sleep.



“Why didn’t you heal your eye." Diluc asks, though it’s less of a question and sounds more like a demand. Kaeya knows exactly what he’s talking about.


He flips the eyepatch, revealing where an empty socket remained from the injury, chuckling as Diluc frowns and looks away, his discomfort obvious.


“I like seeing you squirm.”



When a vampire goes for his throat, sharp teeth bared and poised for the strike, Diluc doesn’t bother getting out of the way.


He watches instead, impassive, as its body gets mercilessly flung aside by an unseen force—crashing hard against the cave walls much to the confusion of its brethren.


“Brother,” Kaeya sighs, appearing behind him as quietly as a shadow, “I would appreciate it if you got out of the way when danger comes running at you.”


“That would defeat the purpose of your existence.”


Kaeya returns with a vaguely affronted sound, “If you die on my hand I’ll get in trouble you know.”


Diluc smiles, cruel and uncaring, brandishing his sword as he replies, “That’s the point. So do your job.” And dives right into the heart of the horde that screeches at his intrusion, knowing his demon will be right on his heels.


“Keep me safe.”