Xion knew, once Sora said that he was bringing Riku, that there might be a problem. Or... maybe it wouldn't be. She didn't know, it depended on when he was from, she guessed. If he was before her, he might try to fight. If he was from her time, then it should be ok, but...

If he was after her, from a time where Sora was awake and alright, he might not know who she was at all.

That thought made her stall- how do you introduce yourself to someone who you already knew? Either way, she decided, he deserved to know. In case something happened, if Sora fell asleep again.

So once the silver haired teen was by himself, Xion walked over, making sure her hood was over her face before drawing attention to herself. "Hello, Riku," she said quietly.