Disclaimer: I do not own FFVII or anything in it.

A/N: This was a request, hope I did good

Gaia, not again. Vincent Valentine had tried for two days to ignore the feeling. He knew it was futile; as many times in the past year as he had fought it he always lost. The signals from his mind and body that once seemed subtle and confusing to him had honed into a clear and identifiable pattern. First the shift in the dreams, then the shift in his waking thoughts. The new images invading his mind until he could barely think at all let alone clearly. Then the breaks in control. He knew he could help this group, this very small group of people shouldering the burden of protecting the entire planet. He knew he should help in their pursuit of Sephiroth, in fighting what the maniac was trying to do. But he was more of a liability than an asset if he couldn't keep Chaos under control.

And it wasn't like the moon wasn't going to stop being full every month.

Get up, Valentine. Give me what I need.

Shutup, demon, Vincent shot back, but he knew he would give in. The bright white disk still shined high overhead. What choice did he have?

Vincent carefully and quietly got up and prepared to slip out of their campsite into the moonlit night. Luckily Barret was on watch rather than Nanaki, the big cat would probably hear even him sneaking out. What would his teammates say if they knew what he was doing? How could he even explain?

Leave it here, Valentine. Or I won't call him.

Vincent unholstered Cereberus as directed and laid it on his bedroll. He had to do it. He had to do it because he had to have Chaos call him, the one who was the only choice. Maybe Cloud was strong enough to survive it, but there was only one person on Gaia Vincent was willing to subject the red demon to. Well, actually two. He smirked slightly at the thought of Hojo expiring in that particular fashion, the thought brightening his evening the smallest amount.

He moved away from his team and into the woods, trying to put as many miles between them as the short night permitted. The one they needed was probably already close, and Chaos directed Vincent's travel for him.

Vincent broached a small clearing where the moon shone almost as bright as dawn compared to the deep shadows of the wooded landscape. He moved to the middle and waited, tilting his head up to the sky and listening to the night sounds. It was so beautiful, peaceful. He didn't move when he heard the approach, his sensitive ears picking up the barest rustle of grass. He felt the cold flat of a steel blade on his cheek while the newcomer was still six feet from him.

"Can't stay away, Vincent?" The smooth, taunting voice of the Spawn of the Calamity. Sephiroth. Their sworn enemy. Vincent turned slowly, if he could only kill him now...

Quit with those thoughts, Chaos snarled from somewhere deep inside his own chest, You know I'll interfere with you. And he is armed, and you are not.

Sephiroth laughed at the murderous glare in Vincent's eyes. They both knew Vincent would not act on his desire. It would be foolish, and Vincent was no fool.

"The deal is the same Vincent. I help you with your problem, but I take what I want first.

Vincent shut his eyes; he would submit. Again. Lips softly brushed his own and long fingers slipped into his dark, heavy hair. His cloak was unclasped and spread flat into the grass. Then another kiss, and hands on his face.

"Look at me Vincent."

That voice again. Vincent opened his eyes to see the startling green feline irises peering at him. They struck him as they always did, like those of a wild, caged animal; a mixture of ferocity and madness.

"You know I need more of you than this."

Vincent knew. Sephiroth wouldn't continue, wouldn't progress to the second half of the bargain, if Vincent didn't participate in the first half. Why the villain wanted that he would never understand. He sighed and kissed Sephiroth back, feeling an unwanted surge as their tongues pressed past one another. He felt his clothing being unfastened as he pushed Sephiroth's long, leather coat off his shoulders.

Sephiroth broke the kiss and smiled at him, a thin evil line gracing his angular face. His hands had moved to Vincent's groin, toying with the obvious swelling there.

"As many times as you say you hate me, Vincent, there's always still this."

Vincent growled slightly. "Don't flatter yourself. The demon spreads its influence over my entirety."

Sephiroth continued to smile. "Mine too," he said.

Vincent wondered about the comment, but his mind was jerked away by hands now running up and down his torso, and with another kiss he found himself doing the same to the smooth, beautiful skin of his imposed lover. Mentally this would be so much easier if Sephiroth would just force it. If he didn't insist on conferring pleasure to Vincent's body, primed both from his own self deprivation and the acute need of the demon inside of him. It would be easier if the bastard wasn't so damn... gentle.

They dropped to the ground, onto the red cloak, urgency now rising in both. Sephiroth pressed Vincent onto his back and ran his fingertips over the gunman's lips, along his throat before they lazily trailed downwards.

"Gaia, you're beautiful," Sephiroth said.

And comments like that didn't help Vincent's state of mind much either. Neither did the glinting of moonlight from Sephiroth's bare torso. There probably was never a finer shaped creature on the planet, and reminding himself that this creature was trying to destroy the planet had little impact on him at the moment. He allowed his boots to be removed, and lifted his hips so his pants might be shrugged off. Unable to avert his eyes he watched as Sephiroth removed the rest of his own clothing.

A god he certainly was, the man looming in the moonlight. Some sort of god at least. The long silver hair spilled over chest and shoulders, its tips just brushing the top of his erection. As he leaned over Vincent the gossamer threads brushed over them both. Vincent moaned despite himself. His moan was capped by another kiss.

"I think you're ready for me now," Sephiroth said, and encouraged Vincent's thighs to tilt upward. In truth very little encouragement was needed; Vincent needed this release as much as the demon inside of him needed his.

Sephiroth brought one hand to his own lips and deposited a generous amount of saliva to his fingertips, then spread the slick liquid over Vincent's opening. Of all the things Sephiroth did Vincent always found this the oddest, the most strangely intimate, to use his own saliva. Vincent forced himself to relax, not a hard trick once he had gotten the hang of it, and Sephiroth pushed his engorged phallus inside. Vincent gasped at the feeling of discomfort that was almost immediately eclipsed by extreme pleasure. Pleasure from the pressure, pleasure from the slow, smooth movements inside his body. Vincent grabbed hold of his own swollen member. He wanted this, and he wanted it over. He felt Sephiroth's hand join his momentarily, to deposit more of the slippery fluid there for him. More saliva. Sephiroth's saliva. Vincent stroked himself in time with the other man's rhythm. He would only enjoy the penetration as long as his erection held, and it didn't help to finish before Sephiroth. He had learned that Chaos always waited until both of them were finished.

It didn't take long; neither had a mind to wait. A few minutes more and both cried out into the lonely the night.

Sephiroth collapsed and Vincent reflexively wrapped his arms around the figure on top of him. Stage two would be on them momentarily, and he felt the thing that always visited him at this moment. Something akin to regret, but not for what had passed. But his mind was foggy as he slipped ever downward and the demon assumed control. Huge, red wings sprouted out either side of them, fanning out along the ground. Sephiroth jumped up, barely escaping the grasping claws.

"Submit," the demon demanded in a voice that was half feral, half Vincent Valentine.

Sephiroth smiled, a wicked glint in his eyes. "Catch me first," he said, and jumped out of the demon's reach.

Chaos howled and pursued. He knew Sephiroth would not retreat entirely, or disappear and hide. Because he would not get Vincent next time, at least not willingly so, which was what the silver haired brat wanted. But also because Sephiroth enjoyed this game. The chase was part of it. They would stay in the glade.

And how delightfully quick this prey was. Clever, wily. He had snatched up that long sword to even out their play. Chaos smiled, eyes blazing yellow and mouth full of pointed teeth.

Sephiroth smiled back, feinted, then swung for earnest as Chaos took the bait. But he missed the demon, all of him. It was remarkable given how much demon there was to miss. He was forced to jump away and cover with a flourish of strokes to keep Chaos off him. He knew Chaos didn't like being cut and it made him cautious. Last time he had cut him twice.

The demon attacked from above, weirdly fast and somehow able to keep parts of his body out of the way of the sword strokes. Sephiroth gave up on slicing and dove along the ground, flipping over as he did so and thrusting Masamune upward. It bit into something, at least six inches had gone into the demon's body. They stood and faced one another, Chaos with a slick spot growing along his torso. A stab wound. That was a new one for them, and Sephiroth smirked a little while he waited for the demon to heal itself, waited for Chaos to grin maliciously to let him know they should start again.

But in the end Sephiroth was caught, as he always was, by the unnatural motion of the demon that put him behind him, wings wrapped tight around his body. He hadn't yet figured out how the demon was doing that, but someday he would.

"Submit," the demon whispered from behind his ear, and Sephiroth let Masamune drop gently to the ground. Sephiroth knew neither of them went full force during their game, they never used magic and Chaos made Vincent leave the big gun behind. But he often wondered where they would end up in a real battle.

The wings opened a little to allow a small amount of space between their bodies and Chaos pushed hard on Sephiroth's back to force him face first into the wall of wing that held him. Sephiroth didn't cry out or jerk as one claw punctured his shoulder, drawing blood. Chaos leaned forward, bit the other shoulder, and lapped up the flow of blood there. Sephiroth could already feel the demon's enormous sex organ pushing between his bare buttocks, gratefully slick with a large amount of leakage that Sephiroth assumed was the demonic equivalent to precum.

With little warning Chaos plunged inside his captive, and this time Sephiroth did jerk. Chaos knew he was hurting him with that big barb on the end of his penis, but there would be pleasure too. He concentrated hard, having to ask Vincent for help. Eventually he got what he wanted, the retransforming of the right hand only. Vincent's right hand, smooth, long fingered, and appropriate for Sephiroth's delicate, human skin. He gripped Sephiroth's swollen organ in his human right hand and stroked. The prince cried out a little at that too, maybe in surprise. Perfect. He wanted to hear all those noises from him. Chaos thrust towards his much needed climax, feeding on the mixed sounds of pleasure and pain from his captured prey. A thought drifted through his mind as he exploded in relief and Sephiroth did the same.

There will never be another like this one for me. And at that moment he couldn't be sure if that was his thought or Valentine's. Some mixture of both, he presumed, as his human host was regaining control rapidly, and he wouldn't have his moonlit autonomy for much longer.

"You have to go," Chaos whispered to Sephiroth, who stumbled, dressed, and picked up his sword.

He smiled tiredly back at Chaos, who was clearly struggling to maintain control. Vincent would want to come out and kill him. In a few moments he would have the demon under control again and be able to use it to that end. But Sephiroth would be long gone, as always.

"Next month, then," he said, kissing the transforming Chaos on the lips, "Vincent Valentine."