Title: Raison d'être

Disclaimer: Katekyo Hitman Reborn! is not mine, neither is any anime alluded here

Warnings: reversible seme-uke roles; multiple deaths; sap, sap and sap

Credit: thank you Bandanability and transcendentlyfor beta reading

Author's Note: This fanfic uses British English (single quotation marks for normal speech and some different spellings)

This fic is meant to be the sequel for 'Feat and Defeat' and the prequel for 'For the Love of Hell' but can be read on its own.

Bedhead = the British equivalent to headboard

Riveling = 12th - 14th century shoe of raw hide with the hair on the outside

Chausses = 13th - 14th century tight covering for the legs, each separate and tied to a belt or undergarment

Herigaut = 13th - 14th century gown-like garment with three quarter to full sleeves, generally with the sleeves hanging

Cloche = end of 13th century travelling cloak

Stivali = summer light boots close fitting to the leg and usually in black, but sometimes red

Wab priest = the lowest order in the ancient Egyptian priesthood hierarchy; wab = pure

The fire is still crackling — I know that. I see the flame devouring my body. I am aware that my flesh is crumbling into ashes. And yet, why do I hear nothing? Nor can I feel any pain. The Cavallone boss, the Varia, the Vongola Decimo, his guardians and his tutor are still standing there; where are their voices? And you, Mukuro-kun, won't you send me off with a farewell?

It's happening again: you and I facing each other in a game of life and death. How many times has it occurred? 2000? 3000? I've lost count.

Even at his death, the sun refused to dim its radiant glory. The smoke of his incineration joined the clouds, offering him no compassion in their unison. And the sky — his own element — looked down from its lofty throne, untroubled by the quotidian affairs of humans.

Byakuran cast another sweeping glance at his crowding opponents, but soon found his stare fixed at Vongola's Mist Guardian. The indigo-haired man held his trident without dropping his guard, as though anticipating the Millefiore leader to leap from the X-Burner flare and challenge them once again. Well, he supposed, at least, Mukuro-kun won't tear his gaze from me — that's the best parting gift I can get.

Today, a heathen named Byakuran Millefiore died with a smile on his face. Yes, that was what he had his enemies believe.

Reality, though, was tougher. He couldn't die even if he wished for it. He could be decapitated, poisoned, drowned, suffocated, incinerated or harmed in countless other ways, but what was destroyed would restore itself in time. An ancient protection charm — his dying mother's last endeavour — preserved his life. In another life, he was a crown prince until all his kin were massacred and he became the last surviving member of his clan by default. What was meant to be the greatest blessing turned into an ultimate curse; he had to endure the multiform of lives in different parallel universe. Yet, by the contrivance of fate, no matter where he went, no matter what live he led, his heart remained hollow; his soul mate either did not love him back or died.

In this life, they had been together for but a few days. Before rescue came, Rokudou Mukuro, who infiltrated in the guise of Leonardo Lippi and lost in the fight against Byakuran, had been held captive in the Millefiore base — in the leader's private chamber, no less.

###

'Kill me. Torture me. Nothing you do will bother me,' fleered the illusionist. His playful voice was the only sound in the Millefiore leader's spacious room.

'Fu fu fu fu fu. What you are about to go through will make torture seem merciful, Mukuro-kun.'

The white-haired demon kept his word by breaking his captive in a way no man had ever done before. He bedraggled the wounded man through incessant rapes in the span of a single night, never holding back, for it was within his knowledge that this was only an illusory body and the real Mukuro in the Vindice Prison suffered no physical damage.

Then the Millefiore leader was gone in the morning, off to conduct business as though nothing unusual had taken place.

When Byakuran re-entered his room later on that afternoon, the figure on his bed was as quiescent as the bed itself, exactly as the last time he had left this new toy. Both wrists shackled to the bedhead, Mukuro lay on his stomach, bruised and wounded, with no single fabric hiding his cream-coloured flesh from view.

'Miss me, Mukuro-kun?' he remarked blithely, stripping his white spell uniform with every step he took.

A sardonic answer met his greeting. 'As much as I miss the water of Vindice.'

Millennia have passed; yet why you remained the only one who can make my happy and break my heart, Mukuro-kun?

Without dismissing his playful smile, Byakuran replied, 'You're being mean, Mukuro-kun. How can you compare me to some confinement?'

'Ku fu fu. Terribly talkative, aren't you? You should learn to hold your tongue like Hibari Kyouya does.'

'Trying to make me jealous by mentioning another man's name?' Byakuran pretended to think hard, and then went back to his usual jovial grin when the last clothing article had left his body. 'Hmm, that does work, actually; I am a jealous man.'

With that, the Millefiore leader placed his knee between the Vongola Mist Guardian's thighs and pushed inside once again.

The indigo-haired guardian gave out a jolt as his muscles contracted.

'Fu fu fu fu, you are still wet from this morning's sex, Mukuro-kun.' The white-haired man shoved deeper inside the slippery tunnel so easily he could almost glide.

The captive's shanks shot upwards, stomach sank into the mattress, breath held, eyes bulging. The lofty white ceiling above graced him no sympathy.

'Not going to retaliate? Where has your previous fighting spirit gone?'

The man underneath him offered no answer. Only his muscles undulated as his fingers clutched the bedhead railing.

Fascinated by the ripples on his captive's back, Byakuran kissed them one by one. In contrast to the blows he delivered during their battle, the touch of his lips was so tender, almost ghostly, against Mukuro's porcelain skin, and the Vongola guardian shivered. Byakuran encased Mukuro's hands in his own, inching even deeper.

Mukuro finally emitted a single noise — whether it was a gasp, a sigh, a groan, a moan or simply a slightly louder puff of breath, Byakuran was unsure; it was so quiet, too quiet, he thought he sensed venom in the other man's voice.

Byakuran took his time licking the blood from one of Mukuro's wounds, circling his tongue teasingly on the injured skin.

More involuntary noises came out Mukuro's mouth as Byakuran moved inside his other, lower orifice. Yet, these weren't enough. They never were, never would be. The captive man's ring of flesh kept pulling his ravisher's manhood in like some natural magnet, maddening him with frictions he knew wouldn't feel the same if he were to obtain them from anyone else.

The leader of the Millefiore Famiglia wiggled, gyrating his hips, and was delighted to see the Vongola illusionist's back formed a more conspicuous arch as he did so.

After nibbling the prisoner's ear, the ravisher whispered, 'Say, Mukuro-kun, why don't you join Millefiore instead of staying with those Vongola weaklings?'

'Every day you ask me the same question..., 'the captive replied through gritted teeth, '... and every day I give you the same refusal. What's the point of asking?'

'Fu fu fu. Just attempting communication between us.' Byakuran's tone was blithesome, but his thrusts grew fiercer and fiercer.

I am deep inside you, Mukuro-kun. Can you feel my body? Can you feel my feelings? You are my sole purpose for living in this cruel world — the reason why my thousands of lives were worth living.

A strangled grunt escaped Mukuro's throat. More blood of his was dripping, lubricating both Byakuran's erection and his own crotch. At least, the sensation of pain should provide an entertainment in opposition to the boredom of the water prison.

To Mukuro, it would have been better if Byakuran left him alone as soon as each coition was over, in a way a child abandoned a broken toy. Instead, his captor lay there, next to him. The Millefiore leader would plant ardent kisses onto his neck and shoulders, hands encircling his waist, and toes caressing his legs repeatedly until one of them fell into slumber. Even though the white-haired man could tell how much his captive loathed to be treated as such, it did not discourage him to adopt this style as a daily ritual between them.

Byakuran could not help it: he enjoyed it far too much when Mukuro's delectable body, despite the captive's will, supplely yielded to his touches; how Mukuro's hips shook trembly to meet his thrusts; how Mukuro's back arched deliriously for him; how Mukuro's white fluid gushed forth uncontrollably onto his stomach and the bed sheet; how Mukuro's heterochromatic eyes shut and opened to shoot him with contemptuous glares...

###

The day Mukuro's illusory body gone from Byakuran's bedroom, the Millefiore leader razed through seven bags of marshmallow within an hour. Still, the softness of the sugary gelatine provided no consolation to the pricking pain deep inside his heart.

Even marshmallow bore a special memory in Byakuran's heart — the memory from another parallel life, that is.

###

'Doesn't marshmallow taste better when you roast it, dear?' Attentively watching Byakuran from the other side of their kitchen table, Mukuro sat with his face resting in the palms of his hands. Amidst the steam of their freshly brewed coffee, Byakuran noticed a serene smile adorning his beloved's face.

'It tastes best...,' answered the marshmallow-lover lightsomely, '... when you feed it to me.'

Mukuro needed no further persuasion to comply. The tantalising sweetness of Mukuro's tongue while delivering the marshmallow into his mouth gave him the feeling that their kitchen had lost its floor and ceiling. He pulled the indigo-haired man in a passionate embrace, encouraging his lover to topple him onto the worktop.

Gently, Mukuro lifted one of Byakuran's arms, holding it by the wrist, only to land a trail of kisses along the inner forearm and culminated with a snatch of the last marshmallow from the amethyst-eyed man's hand. With the gelatinous chunk clamped between his teeth, Mukuro invaded Byakuran's mouth once again. His hands journeyed downwards, sliding off Byakuran's trousers and underpants. Byakuran, too, did the same to Mukuro in perfect mimicry. Their shirts came off last. Neither bothered to fetch the lube, which was stored in their bedroom; the olive oil on the same table should serve the purpose.

'Darling, if you keep staring at me so lewdly, I'll be too embarrassed to open my legs for you,' teased Byakuran.

But Mukuro decided to tag along. 'Ku fu fu fu. Then, I'll just have to fill you up with your legs closed, won't I?'

With that, he hoisted both of Byakuran's legs and rested their calves upon his shoulder, while his pubes cushioned his partner's buttocks.

'Ah, Mukuro-kun, you're too — ah — deep!'

The white-haired man gripped his lover's forearms tight enough to leave finger marks. The last thing Byakuran saw before Mukuro's lips claimed his own in a fiery kiss was a smirk.

###

The same smirk lingered on Mukuro's lips even now, as the flame from X-burner continued consuming Byakuran's body. The Millefiore leader wondered perhaps it was better this way. Mukuro obviously rejoiced over his death. He failed to obtain the trinisette which was to be his one and only hope to control the parallel worlds so that he and his beloved might live happily together. Why should he live on?

In this life, Mukuro detested him with passion. Nonetheless, there were times when Mukuro answered his affection with mutual feelings.

In another life, Mukuro would willingly let him spread whipped cream all over his body to be licked clean. They were pâtissiers, pastry chefs who made a living though the art of their culinary masterpieces. Still, this happiness did not last long. On the third month of their blooming relationship, a tsunami immersed nearly the entire town and Byakuran's immortality only allowed his tears to fall upon Mukuro's already drenched corpse.

In another life, Mukuro stood on the other side of the battle plain at Jena, donned in Prussian military uniform. Their horses had fallen before them, and they exchanged bullets from their rifles until Napoleon Bonaparte, Byakuran's commander, scattered the Prussian army. In the momentary peace that followed the war, what remained of Mukuro was his white tombstone among thousands of others'.

In another life, Mukuro met Byakuran in a rodeo contest and they held a wager, in which the loser had to work for the winner for a month. Thus, together, they groomed the horses, fed the chicken and milked the cows on Byakuran's ranch every day. Constant copulations in the room, the stable, the wagon or even in the open air tacitly would have extended Mukuro's stay for life, if only he had not perished while defending their horses from some looting hands. The fatal blow was at the back of his head, which he covered with his cowboy hat. He bade Byakuran to go after the thieves while he himself nursed his minor injuries and kept the rest of the cattle safe. Upon returning with the stolen horses, Byakuran noticed Mukuro sitting outside the fence with a placid smile. He did not realise that his best friend and lover was no longer breathing until the wind blew away Mukuro's blood-stained hat.

In another life, Mukuro was a Wab priest in the Temple of Amun-Ra. He had to bathe with the cold water from the sacred lake several times a day and all hair throughout his body had to be shaven clean, as all priests were required to. None of these prevented Byakuran from loving him. And yet, when it came to meat, priest or not, the Nile crocodiles did not discriminate.

In another life, Mukuro was one of the coalmine workers. The tunnel where he worked had collapsed before Byakuran ever found him.

In another life, Mukuro was a Canadian make-up artist for catwalk models, even though many told him that he was qualified to be a model himself. Byakuran caught him kissing with one of the models and killed the model straightaway. The rage of having his lover died before his very eyes drove Mukuro to stab Byakuran with a nearby fruit knife.

In yet another life, Mukuro was the sheikh of a nomadic tribe. Four wives were already in his possession and the custom forbade him to acquire more. When they camped near the stout pillared city of Babylon, the skirt-chaser obtained himself a free time to enjoy a prostitute or two. Having observed Mukuro's habits of amorous pursue, Byakuran disguised himself into a female prostitute and seduced the sheikh. However, after the carnal pleasure ended, Mukuro, bearing in mind of his responsibility for the tribe, returned to his people and banned Byakuran from his side.

###

Byakuran had tried very hard to forget Mukuro, he really had. He had tasted a myriad of males and females from the most innocent virgins to the most experienced whores ... and yet, no matter where life took him, a part of him was always unswerving from one indigo-haired man.

Closing his eyes, Byakuran recited the spell to go across dimensions. No bone, no flesh, no skin of his remained in the twenty-first century Namimori. Sawada Tsunayoshi and his allies were getting farther and farther. He travelled through multitudes of objects from various timelines — astronomical sextant, teapot, axe, books, steering wheel, escritoire, loom, camera, tractor, windmill, laundry pegs and many more — all blurred into a whirl of colours.

###

Byakuran reopened his eyes. Before him were a herd of sheep grazing in a lush pasture under the stroking heat of the clear summer sky. The scent of grass and unpolluted air soon filled his lungs. Other than a shepherd boy wearing a simple tunic, meagre chausses and rivelings, who fell asleep whilst leaning against a rock, no other human was close by. Unlike the fashion of the upper classes, peasants' attire did not evolve much; in order to determine what timeline he was in, Byakuran had to find other objects to analyse.

There were houses of various sizes clustering around a castle with its towering battlement at a yonder village and Byakuran headed towards them. As he walked, some of the smokes that were curling up from the chimneys unfurled the aroma of flour being baked into bread. He heard some women haggling over the price of turnip in Italian, and their choice of vocabulary, though not nearly as refined, was closer to the works of Dante Alighieri than to what was common in the twenty-first century. He reminded himself, Dante lived from 1265 to 1321 AD.

Next, he discerned a middle-aged man sitting in front of his cottage while planting some pipes onto a piece of hardwood with keyboard-like buttons on its surface. Organetto was a popular monotonic musical instrument from the thirteenth to sixteenth century.

More villagers came into view. Chausses. Mantilla. Herigaut. Cloche. Stivali. Studying their garbs, Byakuran remembered that at the end of the thirteenth century, the once loose and flowing tunics became tighter fitting. So that's the era I'm in, he gathered.

Too immersed in his train of thoughts, Byakuran did not pay attention to the road underneath his feet until a large pebble stumbled on his way. Only then, he looked downwards and appreciated how dear asphalt was in its absence. The road was unsmoothed with jagged rocks were scattered here and there — a discomfort for his soles. Even though he had experienced far more primitive lives in the pre-historic epoch before, he could not deny the indulgence of technology. After being accustomed with the electricity and other conveniences from the second millennium or beyond, medieval life was bound to be bleak. He could travel between dimensions, but he was incapable of choosing which. Nor was he able to leave it until he was mortally harmed.

Then a running child's figure caught his eye. The boy was barely four years old. His hair of indigo swayed brilliantly in the breeze. His eyes were as blue as pure, untainted ocean. The blood-red pupil was still a stranger to him, for he was yet to learn the infernal techniques.

'Young master, run not so fast, lest you may trip and fall.' His nanny seemed to be out of breath while trying to catch up.

The child halted for a few seconds and displayed a smile innocent enough to make one think that heaven must be missing one of its cherubs, only to run again, jeering. 'Ku fu fu fu fu. Catch me if you can.'

Eyeing the mirthful boy, Byakuran stood statuesquely. A tempest billowed inside his stomach. It took all his willpower not to reach for the child and hugged him tight. All the words in the world held no power to convey how much the sight before him poured euphoria within his veins.

In true love it's apparent whom life has a reason to live for, o my inevitable dulcet and irrevocable dolour, my quenching feast and plaguing famine, my treasured soul mate and irreplaceable adversary ... my one and only raison d'être, Mukuro-kun.

As the little boy and his nanny's shadows crept further and further away from him, a grin adorned Byakuran's face. Yes, this would do. This time for sure, even if he had the entire world as his enemy, he would make sure his existence carved deep inside little Mukuro's heart.

THE END

How Byakuran won over Mukuro's heart at last can be read in 'For the Love of Hell'