Title: Scientific Method
Rating: R/M for dubcon

Pairing: XemnasSora
Summary: The Darkness lurking in Sora's heart interested him greatly- how much until the Light there as well, burned out?

Warning: Angst, dub-con, not happy, etc.
Word Count: 2863
During KH2, which means tiny potential for spoilers?
A/N: For my beta, who provided me with this prompt and puts up with my shit!writing and makes it better. 3

-

Prompt: AntiSora
Pairing: Xemnas/Sora

---

Becoming a Nobody had changed many things about Xehanort (now known as Xemnas) though at the same time, many things had stayed the same. He lacked remorse about what he did, had done, and eventually what he knew he would do to achieve his ends but he did not care; why should he be the one to worry about such trivial things? The humanity that came with a heart was lost, yes, but even as he desired to get it back there was still the part of him that relished in the utter freedom that came with not having any regrets about what he did because he was more efficient than he had been in the past. He knew very well that he could manipulate those around him as well; he knew that he could utilize the desires of the other Nobodies and twist them to further fit his own desires.

Then there was the bit of him that he would never use- the scientific part. The part of him that was ingrained into him as deeply as any other aspect of his personality- it was the part that kept him going through everything.

It was the scientific part of him that analyzed the movements of the boy-child who had set out to destroy all that he was working toward. The two fools with him simply followed their orders and rarely deviated from anything he had observed them doing yet. The child, however…he was a wildcard. Multiple times he had seen the Keyblade wielder leave the protection of his companions, looking for something or sometimes, someone. He possessed powers that even Xemnas was unaware of and while it frustrated him in a way, he also took in each detail and filed it away for later use.

It was with great surprise that he watched the teen fight his way through hoards of Heartless, flashes of light flickering through the streets as they died. With a quick flick of his fingers, he summoned more, curious to see how the boy would react. Every once in a while an anomaly occurred; the boy would evidently call on new powers and one of his companions would vanish, their power appearing to become his own.

Xemnas watched from atop a skyscraper, recalling the memory of the gold clothing the boy had merged into the last time; curious, he summoned more Heartless, and a few more Neoshadows than normally appeared. The boy didn't hesitate at all; he moved as if he had grown up fighting- maybe he had, maybe not. It made no difference to him. What did make a difference was the sudden ripple in the air as the boy froze the power and magic pouring off of him in waves and then there was a flash of light that made him glance to the side just a little. The person- or rather, thing- standing there was no longer the little Keyblade wielder that he had grown somewhat accustomed to seeing; in its place was…a Heartless?

Judging by the way that his companions were panicking, he assumed that this was not a normal occurrence. When the boy changed back moments later after decimating all of the enemies around them, nearly collapsing against the nearest wall, Xemnas made a mental note to study this further before he completely exhausted his usefulness.

-

Sora hated it when he changed. Was it because he was weak? Did he change into a Heartless because his own heart was tainted by everything that he was doing? It had only happened after he started destroying the Organization members- maybe…

"Sora." Goofy nudged him in the shoulder gently to get his attention. "Ahyuck, you need to stop worryin' 'bout it."

The dog reached out and ruffled his spiky hair, grinning and continuing forward with easy steps. The faith in him was relieving but it was not enough to make his heart stop aching- how was he supposed to protect the hearts of the worlds if his own was weak like that?

"Sora! Listen to Goofy, and remember, the Gummi Ship runs on happy faces only!" Donald reached out with Save the Queen and hit him solidly in the knee, giving him a bland look when Sora yelped and glared down half-heartedly. Before he could complain any more, glowing eyes rose up around them and once more they were consumed with battling.

-

Sora tripped, gasping out as the air around him seemed to contract and then snap leaving him staggering and finally falling into the pool of Darkness that always came up when this particular form surfaced. Both of his companions were gone in an instant, already aware of the dangers if they got too close when Sora was like that. Donald had yet to perfect a transport spell to a specific area, but it did get them away.

When he pushed himself back up, glowing eyes reflected in the water and on the glassy sides of buildings made him pause- he was a Heartless again. Glancing down at his hands, he tried to summon the Keyblade only to jerk back with shock as his hands burned. Around him, the Heartless crept closer, thirsting for a heart that they could feel, taste, even, but could not have.

One of the Neoshadows swiped at him, black claws cutting through black flesh and Sora felt himself snap as if he was a leashed creature that had been waiting for far too long for his master to release him. Thrusting himself up, he raked his claws through the Neoshadow, hissing with pleasure as he felt it melt away. Then, with a wide smirk on his face he dove into the hoards of Heartless, killing them as easily as he did with a Keyblade but now it was so much more satisfying.

-

After watching hoards of the creatures be felled by the new Heartless, Xemnas grew tired of simply observing- the scientist in him desired a closer look. A portal was summoned and when he exited he was right in front of the creature, examining it blandly. The Heartless loped forward, aiming for where his heart had once been but finding nothing. Confusion was reflected in the golden eyes, as it tilted its head to the side.

Xemnas grabbed the Heartless by the throat, examining it closely and not flinching when one shadowy hand clamped around his wrist and dug in deep enough to draw blood. "Fascinating." He scowled when the creature flailed, hissing and scratching, leaving long claw-marks on his arm. Tightening his grip to where the Heartless could barely breathe, he bit out an order. "Cease."

All at once, the Heartless melted away, golden eyes fading to a bright blue, dark, shadowy skin vanishing and replaced with slightly paler tan. The Keyblade wielder blinked once and Xemnas dropped him to the ground with a solid thump, taking a step backward from the boy and watching as he regained his bearings. The Keyblade was summoned almost instantly and Xemnas found himself very nearly smiling at the look on the boy's face- Roxas.

"Don't you do it too!" the boy ordered hoarsely, getting to his feet and glaring at the taller man while raising the Keyblade to strike. "I don't know who you think I am, but I'm not h-"

Xemnas shook his head, stepping forward and catching the solid weight of Oathkeeper in his hand, ignoring the burning sensation; Nobodies couldn't really feel so it was simply an echo, thus not real. "How much can your light take, I wonder." Xemnas mused quietly, gripping the blade tighter and jerking it from Sora's hand with a quick move before throwing it on the ground. "It's strong, I grant you that, but even your strength must run out eventually."

Sora glanced over at where the blade lay glowing on the ground. "You don't know what you're talking about!"

"Don't I? How is it possible, child, that you are able to change into a Heartless? Is it because you choose to? No, I didn't think so; I think it's because of another reason. Perhaps it is because you are not as strong as you would like to think you are. Your light may not be enough to fight both the Organization and yourself. What will you do then, I wonder?"

Sora's hand twisted into a fist, clenching and then releasing when the solid, comforting weight of the Keyblade came back to his hand. He launched himself forward, feet pushing into the ground, hands and arms stiff in preparation for hitting the Nobody, only to see him wave a hand moments too late for him to stop. With a quiet noise of shock, Sora hit an invisible wall, stumbling and falling to his knees but the Keyblade was still held out before him- if there was one thing he had learned after two years of fighting it was to never drop your weapon.

"I have a hypothesis," Xemnas murmured, flicking his wrist to enclose the boy in a cage of Darkness. "Your light is like any other with the exception of the Keyblade helping you. What, I wonder, does it take to extinguish that light?"

Sora growled, slamming his Keyblade against the walls over and over again as tendrils of darkness seeped off of the walls around him and started to creep up his legs. It wasn't tangible enough for him to cut through but it was enough that Xemnas could nearly hear the frantic beating of the boy's heart as he panicked. It took only a short while for it to happen; Sora fell to his knees, the Keyblade wavering in his grip and then his hands were empty, closing on nothing but thin air and then his eyes flashed golden for a split second. Sora growled out a curse, slamming his hands against the cage, fighting to summon the Keyblade.

"Why do you struggle?" Xemnas asked rhetorically, circling the kneeling boy. "'Open your heart to darkness.' Those were the words that were spoken to your Riku once and you saw the power that he was able to attain." Sora shook his head, swiping at the seeping darkness which was slowly becoming more tangible as it gathered around his knees. It shouldn't affect him like this! Wasn't he supposed to be the wielder of Light- was…was he getting weak? Biting his bottom lip, he slammed his hand down on the ground and fought to keep the Keyblade in his hand, ignoring the burning sensation as the Keyblade reacted almost violently with the Darkness surrounding him. "That must take a good bit of effort- it makes me wonder- why couldn't Riku resist? Why-"

Sora jerked his head up, glaring at the Nobody with pure anger. Part of him wanted to demand where his friend was, the other part knew that he would get no straight answer, if one at all. "Don't you dare bring him into this!" His eyes flashed gold again and with a final fizzle of magical energy, the Keyblade was gone and no amount of fighting with himself could get it back. Nails digging into the material of his gloves, Sora tried to drag in a solid breath, only to choke on the thick air, the Darkness making him cough and sputter.

Smiling, Xemnas moved closer, standing just outside the cage. He could feel the Darkness wrapping itself around and inside the boy and in that instant knew that he could control him to a point. "Look at me, Keyblade bearer. Get up and look at me," he purred, smirking at the helpless look of shock on Sora's face as his body moved on its own, limbs jerky and unstable but they worked nonetheless. "We control the Heartless as well, don't you recall?"

The boy's glare was very nearly acidic as he stood there, blue eyes flashing to gold and then back again every once in a while. Distantly, Xemnas wondered just how far he could push the boy until he broke. If he was able to shift into a Heartless and keep his heart and he had already became a Heartless and changed back, then it seemed reasonable to assume that nothing short of straight-out killing the boy would eliminate him. Were he to change him to a Heartless again, no doubt Roxas would try to seek him out again, or worse, attempt to do what Sora himself was trying to do. No, he didn't need that headache right then, but what he could do was see how far the boy could be pushed.

"Enjoy this," Xemnas purred the order, stepping forward with that damn smile on his lips. "The Heartless in you is thirsting to get out, I can feel it." And he could feel it, distantly, like a vague taste on the back of his tongue, something bitter and yet familiar but still only an echo of what he once knew. The boy would be unable to fight back, of that he knew. His power over the Heartless was too great for even the Keyblade bearer to resist his will and moreover, the Heartless knew that he was part of the reason that it was able to get hearts- it wouldn't be stupid enough to eliminate the reason it survived.

"Don't touch me!"

Xemnas ignored the choked-out order and pressed the boy against the wall of a building. Sora bit out a curse when he pushed aside zippers and belts, he hissed when glove-clad fingers started to work on his zipper, he gasped when a hand cupped him and he jerked back when the hand stroked, teasingly sending ripples of unwanted pleasure through him. "Stop fighting, boy; it does you no good."

Eyes clenched tightly shut Sora did the exact opposite; he tried to push down the darkness that roiled down inside him, tried to summon the Keyblade, tried anything as Xemnas' hand curled around his cock, just on the side of too tightly. Pursing his lips slightly, the Nobody realized that perhaps force was not the best strategy when dealing with the brunet. "Little Keybearer of Light," he breathed, pressing his lips to a spot just under Sora's jaw- a pseudo-caring gesture- and hearing his breath catch, followed by a ragged, broken little noise. "Look at you, falling so far. It's taken so little to draw the Darkness out of you, taken so little to start extinguishing that Light that you seem to treasure so much- less effort than it took for Riku, even. What will you do when not even your Keyblade will not answer your call?"

Unbidden, Sora's hips jerked up, the dry rasp of leather against his cock wringing quiet little noises from his throat as his cheeks burned a bright red, a mix of arousal, embarrassment and anger. Enjoy it, Xemnas had said, and the Heartless part of him basked in the attention, forcing its way up again no matter how hard Sora tried to fight against the sensations and himself. A second later, fingers pressed to his barely parted lips, the unsaid command obvious. "No," he gritted out, head jerking down and feeling heat build in his stomach even as he felt nauseous. The Heartless in him pressed him forward and the overwhelming hunger joined the dizzying rush of emotions and sensations. A gasp of shock escaped him when the hand slid lower, the angle awkward but the intentions obvious as gloved fingers pressed against his- "No!"

Xemnas' hand withdrew slightly, only to resume the maddening slide that was quickly making the heat reach nearly unbearable tension; his hips arched wildly and with a quiet noise of mixed shame and release, he came, falling to his knees a moment later as the Heartless took advantage of his moment of weakness, rising up and shifting him. Darkness seeped off of him in waves and when he rose up a little onto his haunches, his eyes were pure gold and his skin was as dark midnight. "How long can you stay like this before your heart is completely eclipsed in darkness, I wonder?" he mused, reaching out to take the Heartless' chin in his hands.

The creature hissed, jerking back, stumbling and falling on the ground, limbs askew.

"Sora! Sora, where are you?"

Both the Nobody and Heartless' heads jerked to a shadowy alley where the familiar voice of the duck came. With a quiet hiss that faded into a whine, Sora shifted back to normal, pale, shaky and with glassy blue eyes. Smirking, Xemnas summoned a portal, filing away the knowledge he had gained for later use and stepped into the portal.

Distantly, Sora was aware enough to fix his pants, though his fingers didn't seem to want to work with him- they trembled fiercely and made it take twice as long to fix everything up. By the time his two companions showed up, he was still on the ground, still pale, but he knew he could pass it off as exhaustion.

Two days later, he fought Xemnas with everything he had and when he tapped into a new power, something he called Final Form, he vowed to use it every chance he got to keep his Darkness away.

-

Reviews are wonderful! Crits, what you thought, what you liked, etc, all loved. I know this is different than what I normally write, haha.

Have a wonderful Easter and thank you for reading!