Author's Note: I was supposed to be posting this and I posted one for the Prequel instead. Whoops. Oh well, now you have two new chapters! This is the last one for the crossover sequence! But never fear, we will undoubtedly have more crossover scenes in the future. Also, this scene was also written from Riku's POV, but that wasn't really chapter-worthy length and it just couldn't get combined with anything. Rar may post it in ASAS sometime later. Anywho, enjoy!

Unfortunately, Roxas and… Xion decided to push him forward, so he landed face first in the sand. Vexen grimaced, pushing himself up and spitting sand out of his mouth. This would be the second time this week that he'd been forced to the ground. At least, this time, no one was holding him down, and he wasn't in front of Xemnas, either.

However, he ended up with another face-full of sand as Riku—his Riku Replica—scrambled backwards and kicked more up in the process. He coughed and pushed himself up the rest of the way, dusting himself off.

"There he is!" Riku laughed (too cocky for his own good, in Vexen's opinion. Always had been). "I knew you were around here somewhere. The experiment went well, I hope."

Cocky and sarcastic… hmph.

"I'm technically not finished," Vexen corrected. "I was rudely interrupted." He cast an annoyed look up at Roxas and Xion, not that it changed anything. He doubted they even cared, but he did have his pride to consider.

"Now you know how I feel," Riku said.

Vexen shot a glare at him. If he kept this attitude up… well… Actually, there wasn't anything Vexen could do about this attitude. That didn't mean he liked it.

Riku got to his feet, stretching as he did so. "Anyway. We should probably get going, before Vexen gets started on anything again."

"Yeah! You won't be able to get him to stop!" Sora agreed, laughing.

Vexen thought about being offended. He really did. But… it was true… and… And wait a minute. "How is it that you and Roxas are separate?" he asked, eyes narrowing as he studied Sora. Then Kairi. "And you and Namine? Shouldn't that…" He frowned. "…not be possible?"

"Ah, funny story, actually!" Roxas said. "We're all partial Replicas, now. Ah… one of your Replicas had a separation program all set up."

"It was 42," Namine said. "You'll probably want to ask him about it."

Vexen nodded. "I probably will, this is absolutely fascinating!" He grinned a little, both with the sheer fascination he had about this, and the pride he suddenly felt for 42. "How, exactly, does that—" He paused, noticing that Riku was clutching his head, like it hurt.

Ah… which meant his other experiment was proving successful.

"Are you okay?" he asked Riku, though, just to be extra sure. This sympathetic backlash he got of Namine's meltdowns couldn't be a pleasant feeling.

"Headache," Riku mumbled, probably trying to brush it off.

"That looks like more than a headache," Riku—the real Riku—said, suspiciously.

Vexen saw Namine bite her lip out of the corner of his eye. Clearly she was worried, too. Or suspicious. He'd never been good at reading her emotions.

"Is he actually alright?" Kairi asked.

"I… think so…" Namine replied, slowly.

"Ah, I think he's right," Vexen said, quickly, getting to his feet. "We should… get back to the other universe."

"Is something wrong with him?" Xion asked, folding her arms across her chest. She was frowning.

"No, but I'm sure he won't want to try and keep this conversation going when he has a headache," Vexen told her, tersely. He opened a dark corridor off to the side and out of the way. "Sorry to cut it short—"

"No problem!" Sora assured him, grinning. "And Riku, you should stop by another time! So we can keep talking from where we left off!"

"Good idea," Riku—his Replica—mumbled, stepping through the corridor, obviously very distracted.

"I'll have to stop by another time myself," Vexen said. "I have more questions about…"

"A lot of things, we know," Riku—the real one—interrupted. (He was going to have trouble keeping them straight in his head… thankfully they were leaving now.)

"Another time, then." Vexen sighed, getting the feeling that no one here wanted to really talk to him, anyway. He stepped through the corridor after Riku, and grimaced. "Ahh… Wrong universe. We're still in… this Castle Oblivion."

He'd thought this Castle Oblivion was sealed off, still. Though, if he'd thought it through, of course it wouldn't be. Xehanort was gone now, and there were no threats to warrant keeping it—

"Why'd you bring us here!?" Riku shouted, interrupting his thought process. Vexen jumped a little, and opened his mouth to explain, but Riku kept shouting. "Is this another one of your stupid experiments?!"

"No!" Vexen protested. "I- I just did what I normally do to get back to the other universe!" His words weren't coming out nearly fast enough. "I didn't expect to—"

"You're lying!"

Riku was practically screaming at this point, his eyes wide with fury, hands clenched into fists, his breathing heavy. Obviously, he was upset. Furious. …scared?

The thought of Riku being scared was almost laughable, then Vexen remembered where they were standing. It wasn't laughable. It wasn't even surprising. He cursed himself for not thinking the whole where-he-was-forming-a-dark-corridor-to thing through. Even if this Castle Oblivion had been sealed, he shouldn't have tried to go to it. He should've just tried to go directly to the other universe.

Though, he wasn't sure how being in the Castle Oblivion of that universe was any better… but those were thoughts for another time.

"No, Riku, I swear—"

Riku wouldn't hear any of it.

"But why'd you bring me here to begin with? This universe?" he demanded, his voice strained. He'd gone tense, as if trying to collapse in on himself… to protect himself. "Why- did you just want to put me in front of her? Watch me as I panicked?!"

"You didn't panic…" Vexen said, calmly.

"Yes I did!"

Vexen took a deep breath, biting his lip, trying to hold all the emotions he was feeling right now back. He needed to be calm, for Riku's sake, regardless of the fact his heart was aching like it was.

"You did fine, after-" he began.

"That doesn't matter!" Riku interrupted, again. "I- I dealt with it because I had to and maybe I'm not upset about seeing her but I didn't want to and you just drag me over here? Like I'm still—"

He broke off.

Vexen swallowed, though he had a feeling how that sentence was going to end. He dreaded it.

"Like you're still… what?" he asked, anyway, though he had plenty of guesses. One of them involved the word puppet. Another, toy—though only Larxene had used that word.

"Like…"

The subject clearly frustrated Riku. He ran a hand through his hair—that nervous twitch of his. Well, not nervous, but it certainly wasn't new. He did it every time something frustrated him.

"Like Castle Oblivion all over again…" Riku mumbled, eyes fixed on the ground. "Like I'm just…"

He wouldn't finish that sentence, either. Though, it was the same sentence. The one he'd started but refused to finish three times now.

"Go ahead," Vexen told him, gently. "There's no need to worry about hurting my feelings or anything."

"Like I'm just an experiment to you," Riku said, finally.

Vexen suspected as much. Then Riku laughed, a sharp and bitter sound. It made Vexen cringe a little.

"Not that I care what you think of me," Riku continued, firmly. "But it's not exactly nice to feel like I'm anyone's experiment."

Vexen understood that feeling, very well. The way Xemnas had said his name—he still remembered that very well—and how it made him feel like he was nothing. Not just nothing, but property. Worse, Xemnas' property. It felt awful. He doubted that feeling like you nothing more than someone's experiment felt any better.

Though, honestly, he wouldn't be surprised if Riku also felt like he was…

Well…

"I'm sorry," Vexen said, and he meant it. "I got excited, and…"

He trailed off. Riku refused to look at him. That wasn't a surprise, either. Hardly anything about this conversation was. Even the walls around them were familiar.

"You could've at least asked," Riku muttered. "Or told me. Or…"

"I will next time," Vexen assured him.

"There won't be a next time."

"Hypothetically," Vexen said, chuckling a little.

But Riku was right. There wouldn't be a next time. Not like this. It shamed Vexen to admit it, but he had treated Riku like he was only an experiment. Like he was… property. Forcing him into this without his consent. Forcing him into this without even preparing him for what was going to happen.

Granted, doing either of those things would've changed the results of the experiment. If Riku'd had the knowledge of what he was—

Vexen stopped his thoughts there. It didn't change anything. The results would've only been altered slightly—and it certainly wasn't enough to excuse how he'd treated Riku. Nothing would be enough to excuse how he'd treated Riku.

"Why did you drag me over here, anyway?" Riku asked.

"I… did want to see how you interacted with Namine," Vexen admitted. Riku hadn't exactly been wrong in that accusation. "Yes. But I also thought I'd… test more of Alpha's hypothesis. If Namine—you know… heh… your Namine—had a meltdown while you were in a completely different universe, then—"

"Yeah, but you should've waited," Riku interrupted. "I mean, she just had nine. The chances of her having a tenth this week?"

Ah… Riku had a point there.

But…

"Isn't she having one now?" he asked.

Because, if he was correct (and he had a very good feeling that he was), Riku's headaches correlated with Namine's meltdowns. Especially the headaches that came out of nowhere like this.

"Right…" Riku said.

Vexen opened his mouth, then closed it. No. Now was not a good time to further question Riku about this correlation between Namine's meltdowns and his headaches. Riku probably didn't have much of a clue about it, anyway, except that it existed. Regardless, now was not a good time. Riku wanted to get to Namine, and, frankly, Vexen was starting to feel very uncomfortable about standing in this Castle. For some reason, it felt so much more… sinister than its counterpart in the other universe.

"Ah, we should get back, then, shouldn't we?" he asked Riku.

Riku nodded. "I'll form the corridor."