A/N: So this has been in planning for what, a year now? *sweatdrop* If one of my plot bunnies lasts this long, though, I'm pretty sure it's worth writing. It's been fun so far, anyway. I have quite a few chapters of this drafted already, but I'm going to try and finish up some of my multichapters that are closer to being complete before I devote too much effort to this. Of course, if this is my lowest priority, chances are I'll get all sorts of inspiration for it. ^^; Basically don't count on me being consistent, but any of you who read my fanfics before this already know that.

Happy Aqua/Vanitas Day, guys!

EDIT 2/1/2024: Hello! It's been 10 years! Wow! If you like this fic (or are just now reading it), I HIGHLY recommend going over to Cast a Shadow: Final Mix on my profile instead! That version is edited to generally sound a little better, and also continues on to the two sequel fics, the latter of which is still being updated at this time. Thanks!

XXX

There was nothing. For a few horrifying, breathless moments, there was nothing. No X-Blade – shattered – no fighting – so still – no Ventus – only half again – no Aqua – dead…?

I…

And then there was less nothing. The feeling of tight, stifling clothing stretching across his skin. That stupid suit. Can't even get rid of it by dying… But if he could feel that, he couldn't be dead, could he? At least, not yet.

I… don't…

Sinking. His stomach dropped; the darkness pressed in on his eyes and made it impossible to tell how far he was falling, but a cold breeze whipped upwards into his face, through his hair – hey, I have hair – so he must've been falling fast.

He didn't particularly care where he was falling. I should care, right? Why don't I care?

Ven's heart attached to the light, he remembered. Maybe I'm just becoming one with the darkness.

His sightless eyes widened as he realized he did care. Darkness was under his control, not vice versa. It wouldn't get his heart.

The vertical wind sped up – he was falling faster, faster, and did he just see something? Blue. Glowing spots of blue, scattered across the ground above him, fluorescent holes of light. And yellow microscopic specks, too, like stars. What?

Before he could determine the source of any of the lights, he crashed to the earth like a rogue meteor.

XXX

He wasn't sure how long it took him to wake up. Time felt asleep itself. However long he was unconscious, though, it wasn't long enough to relieve the pain of a headfirst impact of enough force to make a crater in the rocky ground.

The base of his helmet, the metal part cupping his chin and jaw, was still present on his head, but for some reason the glass that would've actually protected him wasn't. With a mental command, it spread over his hair and face, tinting his vision even darker than this dark place already was. If only he'd done that before sustaining a concussion…

Why should I get up? He wondered. It wasn't long before a convincing enough reason came to him: he was bored. Sleeping was boring. If he was just going to sleep and wallow in pain in this hole, he might as well be dead.

So he got up, climbed out of the crater, rubbed his throbbing but somehow not-crushed head – well, helmet – and looked around.

Those yellow specks were a lot bigger up close. Really close, almost-touching-his-face close. And even to a heart of pure darkness, the horde of them packed around him was incredibly creepy.

Heartless eyes. He – Ventus – no, the two of them when they were whole – had seen them before, but that was so long ago. Master Xehanort had made the Heartless attack him, and the panic and fear had split their weak heart. He backed away, but another Heartless, a Neoshadow just like that fateful day, blocked his path.

"Back off," he snarled, summoning Void Gear and taking up a battle stance, but the Heartless barely reacted. Its antennae twitched curiously, as if asking what he was doing. But none attacked, not even one.

"What are you staring at?" He snapped. The Heartless made unintelligible noises, sounding like the tide washing over a rocky beach, and then they slowly dispersed, losing interest in him.

Why aren't they trying to kill me? They were darkness, so – wait, without Ventus, he was only darkness, too. To them, he might as well be another Heartless.

Well, that would be a huge advantage if he was stuck in the source of all Heartless, which was the only place this could possibly be: the Realm of Darkness.

He suddenly let out a maniacal cackle. "The Realm of Darkness!" Fate was stupid if it thought this was a punishment. He was born for a place like this. No more light slicing at his heart like in all those bright worlds.

"Hah, who needs a X-Blade when I've got this whole Realm?" This was what the X-Blade War would've done anyway, right? Plunged the whole World into darkness? Now he had that all to himself – he didn't even have to share with that idiot Xehanort.

He grinned demonically. "This is going to be perfect."

XXX

…Or maybe not. Sure, he could do whatever he wanted here, but he couldn't get any dark corridors to open to the Realm of Light, the Heartless were idiots not even worthy of a sparring match, and the landscape was dull for as far as he'd explored.

"This sucks," he decided. It was so boring. He'd resorted to summoning a few Unversed for company, but they ticked him off so he killed them, and then his heart writhed in pain. So he preferred not to do that.

It wasn't like the Heartless were entertaining, either. With no hearts to steal, they'd occasionally pick fights with each other, and the winner would "eat" (more like absorb, really) the loser and gain its stolen hearts. None of them dared to attack him, though, since he was the darkest of the dark. Even if he attacked them first, their retaliation only lasted for a few minutes before they fled to save their worthless half-existences.

So the most interesting option was exploring. He never slept in the same place twice; his legs carried him for several "days" until he took refuge in caves or craters or just slept under the purple-black sky. He wasn't sure how much longer he would've lasted without going insane if it weren't for the sudden Heartless migration one dawnless morning.

He yawned and stretched up, popping his spine. Sleeping on solid rock was going to be the death of him someday. Not that he'd ever had a comfortable bed, or anything remotely comfortable for that matter.

Hopping down from the stone platform that had functioned as a makeshift bed, he landed on a Neoshadow's foot. It shoved him aside in its haste to get to… wherever it was going. He shot off a Fire at it, only to have a Darkball crash into his face, knock him to the ground, and fly after the burning Neoshadow.

Neoshadows, actually. And Shadows, and Defenders, and every other Heartless he knew as well as a ton he didn't. They swarmed over him without care until he roared up, keyblade slicing through semi-tangible bodies that came too close. The stampede got the hint and formed a bubble around him, like he was a rock jutting from the center of a dark stream.

"What is going on?" He asked, not that anybody would answer.

And then he smelled it: a rich, pure, clean scent, like freshly-washed cotton dipped in nectar hanging from a cherry blossom tree. He didn't know how he recognized those scents, considering he'd never smelled any of them before. At least, not in his memory. But he could feel the tugging in the pit of his heart that could only mean one thing – light.

A light in the heart of the Realm of Darkness?

He couldn't have resisted it if he tried; the Heartless were sweeping him along, and the scent was strong, and his primal instincts drove him like a moth to flame, like any common Heartless. Plus, it was the most interesting thing that had happened in his time here. Probably the most interesting thing that ever had or ever would happen again, too.

How long has it been since I felt…? It was when Ventus… No, I don't miss that… So why am I…? Not like there's anything else to do…

Using catlike agility and tracking skills only gifted to a heart of pure darkness, he wove his way through the Heartless pack. Deformed pillars and jagged rocks served as springboards that allowed him to practically fly over their heads.

The scent must've been even stronger than he thought, because after what he guessed was hours he still hadn't reached it. He'd left the majority of the Heartless in his dust, but he was so exhausted that he had to sleep, and by the time he woke again they had caught back up.

Two more "days" passed. The scent grew overpowering; his eyes watered, dizziness slowed his progress, but he kept tracking it. The Heartless, when he saw them, grew even more agitated. What could the light be? What was it doing here?

Curiosity won out against discomfort, so he kept going.

He was close now; he could feel it. The massive cluster of Heartless was a big clue, too. So were the faint but determined battle cries… familiar battle cries…

He stood at the edge of a steep cliff that protruded into the inky sky. The tip of it was so narrow that he tested his weight on it first to make sure it wouldn't crumble into the chasm below, but it stayed firm, so he stepped forward and looked unflinchingly towards the ground.

The cliff wasn't so tall, at least not as tall as he thought, and that wasn't a cavern – the mass of dark creatures, more than he had ever seen in one place, even in the Realm of Darkness, created the illusion of depth.

The pure scent of light wafted from the center of the dark mass, blown upward by a fresh breeze. He took a deep breath, the immediately coughed it out. It scoured the inside of his throat like acid, but he still had to get closer.

He'd stared firing a barrage of Dark Blizzaga on the Heartless below before he realized what he was doing. It wasn't very effective; while it was a momentary distraction, the Heartless' lust drove them to fight to devour the light without any sense of self-preservation. He tried mentally commanding them, the way he did with his Unversed, but their dark clouds of "emotion" blocked him out. By now he was pretty fed up with the Heartless in general. What right did they have to the light? He was the strongest darkness; he deserved to eliminate the foreign light.

Without a second thought for the force of gravity, he jumped from the cliff. The fall lasted a fraction of a second; the impact caused him no pain. The vicious reaction of the Heartless mob, however, did. Wyverns dive-bombed him; Darkballs snapped at his arms; Neoshadows tried to drag him into their dark pools. With a roar he summoned his keyblade and slashed through them with a deadly combo. A Wyvern counterattacked by scooping him up in its talons, flying up, and dangling him over the horde at a much greater height than the cliff.

"Let go of me you overgrown- uh, actually don't let go. Or I'll bash your skull in."

Apparently he still had some power over the Heartless, because it didn't drop him. Instead it gave a shrill skreee and shifted him to its other foot.

From this angle, he managed a glimpse at the source of the light – only a glimpse, but it was enough.

I knew I recognized that voice – wait, what is she doing here?!

He barely had time to wonder before the Wyvern plunged into a steep spiral dive, straight towards the girl he recognized.

"Hold on stop you idiot stop!" He yelled at the Wyvern in vain. They were a split second away from her – and the very solid ground –

Her keyblade dissolved the Wyvern just before it headbutted her, but that didn't stop his momentum. He managed to tuck his head and roll across the craggy ground without breaking any bones. That didn't mean he wouldn't feel bruised and broken later, but right now adrenaline was pumping through his veins so frenetically that he barely stopped to catch his breath.

"Hey, losers," he called over the roars, grunts, and hisses of the Heartless. He didn't spare himself a glance at the shocked, apparently speechless girl beside him, though her horribly pure smell was overpowering him in a way it never did in the Realm of Light. Couldn't get distracted now; the Heartless would jump on any scent of weakness.

He summoned a ball of Dark Firaga and held it high as a warning. This better work, or—Well, he didn't have time to think about it.

"She's mine," he declared to the Heartless. They quieted slightly at his voice. "You hear me? Mine. So if you want your worthless nonexistences ripped to shreds, just try to take her from me."

Sure, they'd paused for a moment, but now the Heartless didn't seem impressed by his threat. Several Neoshadows slashed at the girl in unison, but she could only block so many claws. The last slash landed her flat on the ground with a broken cry.

"I said, she's mine!" He snarled, destroying the Neoshadow and other nearby Heartless with his Dark Firaga. The girl writhed from its toxic heat. "But if that's how you want to play…"

He finally allowed himself a clear look at the girl. Blue hair was the most striking attribute at first; he knew her blue eyes would be too, if they weren't closed. Dark scars, bruises, and blisters marred her exposed skin – which she had an overly large amount of, especially compared with himself. Her right sleeve was in tatters, one of her pink chest-straps hung loosely where it had snapped, and that odd skirt-like thing she usually wore tied around her waist was missing.

In summary, she was broken. He could finish her off then and there. Finally have vengeance on the girl who had killed him.

But even as he pressed his keyblade to her throat, a voice in his head whispered, Then what?

The girl coughed up blood. Her eyes opened narrowly, but where he expected to see bright blue, full of loathing for the abomination she had killed, there was only cold, dead grey.

"Kill me," she muttered. Her voice was like gravel. "At least…" she coughed, "then this nightmare will end…"

The Heartless wouldn't wait forever for him to make a decision. So he made one.

He summoned an orb of pure darkness and shoved it down her throat.

XXX

"You're heavier than you look," he said as soon as she regained consciousness. She hadn't opened her eyes yet, but he could tell from the shift in her breathing.

When she coughed, dark violet smoke, the same color as the fire he was stoking, drifted out. "What did you do to me, you-" He didn't find out how she planned to insult him this time, because another coughing fit wracked her body, and she curled back into the fetal position.

"You mean besides saving your life?" He smirked under his mask. "I used a spell to cover up your light, single-handedly fought off the remaining Heartless, and carried you all the way here."

He didn't mention that there were less than fifty Heartless remaining once they thought her heart was gone, and the cave he'd carried her to was only a few yards away. But still, the fact that he'd saved her life should've made her a little less critical.

She didn't seem to hear. He was starting to wonder if she'd fallen sleep again until she gasped out, "Why?"

He shrugged. "I was bored."

It was probably – no, definitely – the most honest thing he'd ever said to her, but she opened her eyes just enough to scowl at him. "Why… should I believe you… Vanitas?" She practically hissed his name. It was almost as amusing as it was irritating.

"I don't give two Shadows if you believe me or not. But if I didn't want you alive, you'd already be dead."

She coughed up more dark purple smoke. "What do you… want from me?"

The violet fire reflected eerily off of Vanitas's mask. "I'm sure I'll come up with something."

Unfortunately, she fell asleep before she could grace him with a heated retort. It was too bad; that half-conversation was the most entertaining thing that had happened since he'd gotten stuck here.

He lay down and tucked his hands behind his helmeted head.

"Goodnight, Aqua."

A/N: If anyone's wondering why Aqua isn't too surprised to see Vanitas, she's basically accepted the fact that every horrible thing that can possibly happen will.