Another fill for Dark Month 2012, where the request was pretty much Axel/fem!Roxas, vampirism and serial killing AU.

Not quite as gnarly as my previous one, but pretty … dubious nonetheless. In the Rocks Fall Everyone Dies sense.

This ended up as a weird little AU where 358/2 Days is retold? As a vampire AU? Yeah, I'm not sure either.

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At first, he only stays by her side out of practicality.

He knows what she's capable of – he's seen the murder in her eyes when they're clouded with violence and bloodlust, when she lifts her chin and tilts her head back to lap daintily at her knuckles and then crushes a grown man's skull between her finger. He stays wary because he knows it can be him any moment, the moment she tires of him – or the moment he outlives his usefulness. Perhaps she has forgiven him for subjecting her to this; perhaps she's a pretty little time bomb, counting down the seconds to the moment she will repay him for his kindness.

She's a fickle, fickle thing.

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He finds her docility unnerving.

She is not born of the night and the shadows, not in the same way the others were; she was not always a part of the coven. She was a pretty little thing once, lost and alone in the forests, a nightwalker that did not burn in the sun.

In the sunlight, she is gold and amber – not ash and bones in the wind.

"Who am I," she says. It is more a statement than a question; her voice is inflectionless to his ears, a quiet purr so soft he can barely hear it.

He swallows and holds out his hand. She surveys it, as though committing every whorl and groove of his fingertips to memory. "Come with me. You'll be safe."

Axel wonders if she can hear the lie in his voice. She looks up at him with a glacial stare; her hand in his is cold and smooth and the fine bones are songbird-fragile, so easy to crush between his fingers.

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What unsettles him more is the way Xemnas appraises her – like a priceless commodity, like a slab of meat, like a chemical equation. He picks her apart at the seams with his eyes and smiles, slow and feral and catlike, when he takes in her unblemished arms and the sun-drowned gold of her hair.

"A child of darkness who treads pathways of light," he purrs, and Axel shifts with discomfort at the undercurrent of interest in his voice. "Curiouser and curiouser."

To him, she's but a tool to be used; a hunter to chase down what he himself is unable to pursue. The others of the coven are strong in their own right – but like Xemnas, they too are smoke and dust in the sun.

"Keep her close," Xemnas says. "If she strays, bring her back."

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At first, it is simple. There is no attachment – only business. He teaches her the ways of the hunt and the rules of the coven and watches from afar as she returns dead-eyed and with spotless hands. She is a thing of terrible exquisiteness, a porcelain dancer who rips out the throats of the Organisation's foes with her bare hands; she does not toy with them as Xemnas does, nor does she kill with indiscriminate viciousness, like Saïx. She doesn't stalk them from a distance and warp in to strike, as Xigbar does, nor does she bide her time, not like Luxord. Roxas plays no cruel mind-games as Zexion is wont to, nor does she kill merely for sport, as Larxene and Marluxia do – no, her methods are far more direct., fuelled by the only purpose she knows.

Kill or be killed. It's the only way the Organisation will allow her to survive. It's the only way she can keep her position – she knows as well as any there are others amongst their ranks hungering to be turned, ready to prove their worth as more than just custodians, as executors of diurnal affairs.

Sometimes he wonders morbidly what it will feel like when she realises she is being used, when she remembers that he's the one who immersed her in the only world she knows.

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On the twenty-second day, she calls him her friend.

"But we can't be friends forever," she says, almost apologetically.

He stares into her eyes and wonders if it's a threat. "I'm sorry?"

"We can't be friends forever," Roxas repeats. Her fingers lace and unlace on her lap, pale and stark against the black of her dress; she digs her nails into the silk and brocade and strokes absently at the fabric, as though trying in vain to smooth it down.

"Why?"

She stares at him as though he's stupid. "Because you'll die before me, isn't it? Because you're mortal. I'll still be here long after you're gone."

"How does that make you feel, then?"

Roxas eyes him sidelong as she hunches into herself and tugs idly at the ends of her hair. "Sad," she responds. "And maybe lonely. I don't know. I don't want to lose anyone."

It feels cruel, but he persists nonetheless. "Isn't that kinda against everything Xemnas said? All that about how the only person you should be worried about losing is yourself."

"I've already lost my past," she says and bares her cruel, perfect teeth in a way that makes him think of wolverines and wild beasts. "I don't want to lose my present."

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At some point, he watches her fall in love – but not with him.

It's a strange thing, watching her rediscover the humanity she had shed like a snakeskin when she joined the Organisation; even stranger is watching her eyes round with pleasure at the sight of Xion – he's too accustomed to that gaze being his, too used to being the only one she trusts enough.

Somewhere, he feels jealous; he wants to hurt her – the mortal woman, the fabrication, the homunculus, a pretty doll wrapped in a skein of counterfeit flesh and bone made to replicate the Organisation's prize. It would be easy, too easy, to end her – but Roxas would never forgive him, and somewhere inside he knows he wouldn't be able to forgive himself.

He wants her to be happy; it's the least he owes her, after everything.

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His life is a cycle of looking out for her, for ensuring her own prestigious skill does not cause her own death – and it's difficult, in ways that almost make him regret the way he is in thrall of her.

What she doesn't know won't kill her – or so they said, before he snapped their necks. There are many, too many waiting to see her fall; the coven is a pack of hungry wolves and she's little more than a puppet on a string, just like Xion is.

Traitor, Vexen sneers as he claws convulsively at Axel's hands around his neck. She will never pay you any heed because there's nothing left in her, nothing in her heart but the bloodlust that will end you.

I expected this, Zexion says almost conversationally and smiles through blood-spotted teeth as he attempts to wrench the stake from his chest. His hands close around empty air as he sways and falls and unravels at the edges into bones and dust. You were always an unpredictable one.

What she doesn't know won't kill her, he tells himself as he goads the others into the paths of vampire slayers and torches Castle Oblivion. It burns, baleful and bone-white in the noonday sun, a pyre for those left sleeping within.

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On the hundred and seventy-first day, she asks him what love is.

He and Xion exchange looks. He stutters and shifts from foot to foot – what can he possibly tell her? Love is killing my comrades so that they don't harm you. Love is being loyal to you and expecting nothing in return.

"Love is," he begins, and falters.

Roxas appraises him with the eyes of someone far too old for her face. "Xaldin told me it's something that you hold dear," she says slowly. "He said that to hold something dear is let it hold you."

"Someone," Axel corrects. "But I guess that's the gist of it."

She's silent at first, until her lips quirk into a crescent-moon smile, small and secretive. "I see."

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Lover, she whispers against his palm. Her teeth prick his wrist – but not enough to make him bleed; she stills when she feels his pulse against her lips and then laps at his skin, over the path of crisscrossing veins.

Lover, she murmurs into Xion's hair, and nips at the curve of her throat. There is something needy in the way Roxas moves, in the way she touches and explores, a hunger in the caress of her cold, pale hands.

Help me, she says as she arches against them both and digs her nails into their skin. Don't let me go.

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It is the three hundred and fifty-seventh day.

"I'm sorry," he says.

It is the three hundred and fifty-seventh day and Roxas is cradling Xion in her arms. She is small and cold and fragile and dead and everything is wrong, wrong, wrong.

Roxas throws her head back and keens, a high, visceral sound that makes Axel's skin crawl. When he touches her shoulder she flinches away and curls protectively around Xion. He averts his eyes as she presses their foreheads together and wraps her fingers around Xion's and lifts her face to stare at him, hot-eyed and accusatory.

"You let her die!" she screams; her voice is harsh and strained, high and cold and sharp as glass shards. "You let her die!"

He doesn't argue – because it's true, isn't it? It's the hardest choice he's ever had to make, choosing which friend lives and which dies. He won't forget the look on Saïx's face when the hunters appeared, when he thinks of the Isa he once knew and loved and runs. He can't forget the sad, understanding smile Xion gives him either, even as she falls, hands pressed to her chest as she desperately fights to staunch the blood.

"I'm sorry," Axel says, and he doesn't know which woman he is talking to – the one small and broken and dead on the ground, or the one that glares at him with too much pain in her eyes. "I'm so sorry."

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Lover, she sobs brokenly into his chest. You're all I have left now.

I'm sorry, he whispers into the shell of her ear, into the curve of her jaw and the dip of her collarbones. Sorry, sorry, sorry.

I will avenge her, she says, teeth grazing across his knuckles, I will make sure she did not die for nothing.

And what if you die? he asks as she shudders against him and nips his shoulder and kisses his throat with her cold lips.

If I die, she breathes against his neck, flush against his pulse, will you avenge me? Will you miss me?

I will, he says, and he can feel her cheek curve into a smile against his skin.

I'm glad, she says, and bites down.

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In exchange for some of her power, he fights for her and her purposes; they are renegades now, ghosts in the machine; there is nowhere for them to run, no escape save for hiding in plain sight.

What she doesn't know won't kill her, he reasons as he digs mass graves and covers the faces of his once-colleagues. It's what he tells himself when he steps from the shadows and garrottes Xaldin and poisons Demyx; it's what keeps him going as their ranks dwindle and Xemnas's idle displeasure grows. He's not stupid, he knows what's happening before his eyes but makes no attempt to curb the slaughter; the knowledge of his inaction is what discomfits Axel the most.

Roxas's recklessness grows with the passing days; it festers in her hollow chest, curled in her ribs like an idle serpent. He sees little of her now – she's faded and haunted, a ghost who slips away from the corner of his eye; he leaves her be and shuffles his paperwork ostentatiously loudly, and thinks of burning everything.

She returns one day with blood spotting her cheeks; upon catching his eye, she licks at the edge of her lips and smiles that old, secretive smile. It's the one he remembers from her first days in the Organisation, a hollow smile from an enigmatic toy soldier carved out with nothing left inside.

As she passes, she leaves a deck of cards on his desk.

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The hardest part is killing an old friend.

Business, a part of him whispers. Just business. Nothing more.

It's the only way he can force himself to drive the stake through Saïx when his back is turned. It's the only way he can bear to listen to the crunch of breaking bone, to the ragged hiss which marks the end of his first friendship. "I'm sorry," he wants to say. "I had to do it before you took the only other person I had left," he wants to say.

Instead, he remains silent when his once-friend pivots and bares his teeth, terrible and gleaming in the harsh light of the Dark Citadel; his eyes are amber and scarlet and disbelieving, and Axel feels guilty, so guilty for missing his mark.

"Why?" he breathes. "Does the past mean nothing to you?"

"I've already lost my past," Axel says before he can stop himself as Roxas regards them grimly. "It was lost to me when you stopped being Isa."

"That's enough," Roxas cuts in. "You didn't have to make him suffer as a price of your cast-away memories." She elbows him aside and kneels before Saïx; Axel looks away as she wrenches out the stake, and drives it true.

He wonders when she got so ruthless. He wonders when she began to understand, and when she began to remember.

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"Turn me," he says.

It is the three hundredth and seventy-eighth day and they are running out of time. Xigbar's disquiet grows as the weeks since Xion's death pass; Axel is certain the only reason he hasn't attacked them yet is because of Xemnas, all too secure in the knowledge that they will stand no chance against him.

"Turn me, and I can fight with you."

Roxas takes her time to answer; when her teeth prick the back of his hand, he wants to believe that is her response. "No," she says at last; when she kisses him, he can smell the tang of his own blood, faint and metallic. "Not now. Not soon."

.

Xigbar is waiting for them when they turn their attention to him; he makes no attempt to escape, and the sound of his laughter fills the Dark Citadel, sardonic and staccato. "Come and get me – if you can," he crows, and chuckles when Roxas curls her small, cold hands into fists and restlessly fingers the handles of her swords.

They chase him through the shadows as giant screens fizzle to life overhead, static crackling across their surfaces with the rain; it's a countdown – they're running out of time.

They're always running out of time.

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In the end, it's the old fox's own cunning that kills him. It's his own ricocheted shots that Roxas sends back to him that slow him enough for them to corner him.

His smile is a brittle curve showing far too many teeth.

"Congratulations," he says with the air of a snake spitting venom; it feels like an insult, less like a commendation and more like a curse. "You made it this—"

Roxas lunges at him before he finishes speaking; Axel doesn't miss the triumphant glint of his eyes even as she pins him down and impales him with both swords, like a bug speared on collector's pins.

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"Turn me," he says.

It is the three hundred and seventy-eighth day and Roxas palms impatiently at her wet hair as she storms through the Castle. They leave behind them a breadcrumb trail of rainwater and dank ichor, their progress through the abandoned corridors marked by the discordant scream of metal against stone and a ragged path gouged into the floor.

"After this," she says, half to herself. "After this is all over."

They are walking into a death trap; it's suicide to saunter into the heart of the coven's stronghold and expect to take their leader down; it's madness, all of it – but Axel's tired of arguing against her. "Very well," he says. "I'm holding you to that."

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They find him at the Altar of Naught, a figure of darkness amongst star-strewn emptiness; he is as though cut from nothingness, a void drawing light into itself.

Xemnas smiles in the indolent matter of a cat with the cream. "At last, the light's chosen one. How does it feel, to have given yourself over to all the darkness that you nurtured in your heart?"

Business, Axel tells himself as he circles Xemnas warily and Roxas snarls at the back of her throat, low and feral. Business as usual.

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He doesn't know when it starts. He doesn't know when it ends. All he knows is that Roxas pins Xemnas down with her knees and drives both Oathkeeper and Oblivion into his chest and into the splintered stonework and digs her nails into his throat.

"You become the monsters you fight," he's saying. "Congratulations are in ord—"

Her smile is sharp and predatory and like nothing Axel has ever seen before as she twists sharply to snap the spine – and tears his head off.

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"I made a promise," she says delicately. She's staring at some point over Axel's shoulder; he can see the flames reflected in her eyes, can track each coil of flame and scrap of ash which rises from the conflagration.

"Hip, hip, hurrah," he says. "The coven leader is dead. Long live the queen."

The smile it brings to her face is something he hasn't seen for a long time – it's small and unstrained and genuine. "Yes."

Her hands smell of violence and death. He kisses her knuckles, then her palm, as she turns her hand and curls her fingers, beckoning him to come closer.

Her fingers are cold against his neck, cold against the warmth of his pulse. "I will miss this," she remarks. "Feeling the life in you. Are you sure this is what you want?"

Axel nods as she presses her hand flush against his jaw and tilts his head up.