I do not own Kingdom Hearts or any related games or characters, and I make no money from the writing or submission of this work of fiction.

...I love making Demyx evil. And I think Demyx/Saïx is a highly misunderstood pairing that could be much better than what it is with most of its writers. (A hyper-ass kiddy Demyx and the ever-famous bipolar puppy!Saïx.)

Anyway, this is very highly based off "Only" by Nine Inch Nails. It seems to me like a song Demyx would very easily relate to.

Among the Nobodies of the Organization, Demyx's most infamous characteristic was not his unwillingness to fight, nor his insistence that they had hearts, but rather, his chronic insomnia. It was the reason behind half of his title, in fact. Though the World That Never Was didn't actually have official daylight and night hours, Nobodies still had regular 24-hour cycles. "Night" for them was whenever the majority of the castle was asleep.

Demyx was always awake at some point during this time period. Tonight was good though – he got at least four solid hours of sleep this time. The downside? Everyone else was still sound asleep. As much as he complained about getting missions, he had to admit – they were a pretty useful as a means of distracting himself from his thoughts. At times like this, while everyone else was knocked out, Demyx was left alone with his musings.

He lay wide awake in his bed, wondering about the heart, existence, and nonexistence. He thought one abstract thought after another, eventually getting lost in his own train of thought and needing to start over from square one. This confusion of thoughts had been happening more and more frequently lately, and Demyx no longer was secure about the definition of his being – or non-being – which was right?

Sighing, he sat up and stretched. Storms were rare and far in between on this world, but once they started, it could keep going for days straight. He looked out the window to see that the sky was finally calm again. Great. At least when it was storming, the sound of rain tapping on the window managed to help him relax.

Demyx got up and walked out his room. If he couldn't keep himself distracted, he'd find the one who could – even if for just a while. As he walked down the halls (thank goodness the lights were out), he couldn't help wondering what that new guy, Marluxia was doing on his mission. At the time being, he would have done next to anything to trade places with him; he didn't care what the mission was. Demyx's usual assignments included stealing or otherwise displacing valued artifacts and other items that tended to cause wars and discord, but he wouldn't mind getting one of the Assassin's missions too much right now.

The Nocturne walked to the door that stood between the hall and the bedroom closest to Xemnas's. Its Roman numerals gave a dim, ominous glow, as many random things in this castle tended to. He opened the door and stepped in rather unceremoniously but was disappointed to find that the one he was searching for wasn't even there. Sighing and scratching his head, he walked to the ridiculously huge window. It was covered by a sheer black curtain (now just where the hell did the Organization get that?), probably to block out the bright moonlight without completely hiding the moon. He folded his arms and gazed up at it. Yeah, it was pretty weird for a moon to be heart-shaped, and it did happen to grow mysteriously over time, but the damn thing had better be pretty good if it was what all the Nobodies were striving so valiantly for.

The sound of a door clicking shut caught his attention. Standing in front of it, clad only in the same thing Demyx wore – a black tank top and pants – was the elusive Nobody Demyx had been searching for.

"Gone intruding in other people's rooms now, Demyx?"

"I was looking for you. I wanted to play and my playmate wasn't even here."

"How heartbreaking."

Demyx walked to bed and sat at the edge. He fell back and mumbled, "Mean little puppy."

Before he knew it, Saïx was upon him, hands on either side of his torso, eyes angry, teeth bared. Oh, how he hated that epithet.

Demyx decided to push his luck and tapped Saïx on the nose. "If you rip me to shreds, who're you gonna have to play with?"

"I'd manage to make use of you. Perhaps I may even prefer you torn open and spouting blood."

"But if I ended up dying I'd just fade, and you'd be out of luck. I bet even you have to get away from the Superior after a while. You gotta top sometime, right?"

Saïx growled and pinned Demyx's hands above his head. "You'll hold your tongue about what doesn't concern you, and I won't cut it out." He used one hand to shove a long digit into Demyx's mouth and pressed the sharpened claw against the Nocturne's tongue. "I imagine I might not even need scissors. In fact, I could do it right now."

Demyx moaned and wrapped his legs around Saïx's waist. His hips thrusted up to tease him, turned on by Saïx's aggression.

"Whore," Saïx commented before letting go of Demyx and moving to sit on the bed. Demyx turned over on hands and knees as Saïx opened his pants.

"You know how horny I get when you act like that."

Saïx grabbed Demyx's head nonchalantly and pushed his face down onto his crotch. "Your mouth is much more useful down here."

Demyx giggled and circled his tongue around the head of Saïx's cock. He sucked at the tip, teasing with his tongue. Saïx leaned back on his arms and watched, then began to lose patience and pushed Demyx's head down further. Demyx resisted protesting and took the rough treatment, letting the bobbing of his head remain completely under Saïx's control.

Saïx made Demyx feel so under-appreciated. This did little to faze the boy and instead, came to him as a relief. Hell, feeling was feeling. It was the separation between him and the Berserker. He felt because he wanted to feel. Saïx only knew illusions of emotions because it had been drilled into his head that they were all that was available to Nobodies, and so he believed it. It all came down to what the individual expected to "feel."

"You know, never have I seen such a willing little slut as you, Demyx. Most others have at least some sense of dignity, but you've shown me none yet." His grip on Demyx's hair slackened, allowing the Nocturne to shamelessly run his tongue along the underside of the hardened flesh before him. It was hard to care about how "dignified" he looked in front of a man who claimed he did not even exist.

"Turn around," Saïx ordered, and Demyx obeyed as expected. Saïx reached around to open Demyx's pants and gave only enough effort to push them down to his knees. He spread the cleft of the Nocturne's ass and spat onto the tight pucker. The only further semblance of preparation was Saïx's finger pressing to his opening, spreading the saliva, before Demyx was yanked back to sit in Saïx's lap, instantly being filled. Demyx moaned and squeezed his own cock in his hand despite the pain – or was it because of the pain? All he knew was that it was there, perpetuated by the Berserker's careless pushing and pulling.

Which led to a turning point in Demyx's musings – how the hell could something be in pain if it could not be at all?

"You really are shameless, aren't you?"

Demyx laughed. "Are you complaining?" He briefly clenched around Saïx for an added effect, making the Diviner toss his head back with a stifled moan.

"How can I? Having your own personal slut is hardly anything to complain about."

Ha. Since when was Demyx just Saïx's personal slut?

It was probably damaging to take the verbal abuse Demyx so often received, but Saïx said himself that he did not exist, so what was the problem? Is getting hurt really a problem if a nonexistent creature is hurting you?

Demyx adored the control Saïx neglected to realize he had. When Demyx played with his imaginary friend, whether or not Saïx had any fun was completely dependent upon how much interest Demyx showed. He could get into and let Saïx think he was on top of the damn world, or he could act like he was bored out of his mind and let Saïx feel his little "illusions" of being pissed off.

And that was their difference. Demyx was the creator and the manipulator of what happened, and Saïx was the imaginary friend, pulling Demyx back and forth on his cock only because Demyx let him, always reacting to Demyx's behavior, always acting how Demyx wanted him to.

Saïx groaned and began to thrust upward, reacting to the now-rhythmic clenching around him. His claws dug into Demyx's hips and he had begun to spit out random obscenities to and about Demyx. He was acting beautifully as the fictional and metaphorical knife to the wrist of a man who never really could get into the cutting thing. Demyx arched his back, beginning to get close himself. Whether he was getting off from Saïx fucking him or his renewed existence and ability to feel, he neither knew nor cared. He was cumming, and hard; there was no reason to try to make it something complicated.

Demyx occupied himself with licking the evidence of his orgasm off his hand as Saïx thrusted up madly to reach the orgasm that was just barely eluding him. His throat vibrated in what Demyx would call a growl and he emptied himself into the Nocturne, who was simply unable to resist giggling in response to the feel.

Saïx fell back with tiredness and Demyx took it upon himself to remove the sated organ from inside himself. He ignored the sticky fluid escaping down his thigh, pleased with his performance thus far.

"Close the damn door on your way out," Saïx ordered without the intimate affection often attributed to someone who just got done having sex.

Demyx sat cradling his head in his hand, elbow resting on his windowsill. He was still unlikely to sleep anytime soon, but for now, he had no need to dread being awake. Whenever his thoughts plagued him, a good hard lay from Saïx always managed to return him to this contented state.

He could feel and exist, all because he made enough effort to do so. There was no actual Saïx, or Xigbar, or Axel, or even an Organization XIII, because the Organization's components insisted that they did not exist. Who was Demyx to argue with what they chose to believe?

Who was Demyx, anyway? What was Demyx, anyway? Demyx was the biggest whore in the universe. Demyx was the Organization's favorite oddball. Demyx was God. Let the others exist only as figments of their own imaginations. Demyx could be whatever the hell he wanted to be. Because Demyx was special. Demyx was.