When he saw her traipsing around Beast's Castle, non-keyblade in hand, he thought nothing of her. That, of course, was only the first time he saw her. And he remembered with bitter mirth his first contact with her: scathing words and strikes to her lithe form. The merest hint of ball joints and maybe-porcelain skin. Her fabricated anger and careless lashes. The echo of someone else's face when he looked into eyes that were blue as the skies he sought again, blue with (copied, stolen) light.
Kairi's eyes. Sora's eyes. And now, the doll's eyes as well. At first, he would have killed her for having the nerve to have eyes so similar to his friends', yet be so unlike them. Now … he was not so sure.
After that meeting, it was her who sought him out. She was as much of a puppet as he was (is?), but had escaped her puppet master in open defiance and found him. To Riku, it meant little more than relief; Sora would wake up sooner if she was willing to cooperate and simply self-destruct. He now was loathing the fact that he had aided her in doing just that. Maybe it was because it was not immediate. Maybe the fact that she had stubbornly tried to leave her "friends" with more than they deserved (less?) led to him falling for her. But by now, when she was no longer by his side….
He felt that, in a way, she had given him the strings to move her (the puppet). Had shown him so much of her, confided in him – possibly, he managed to give her a taste of faux emotions. He remembered showing them back to her. And he knew that, with each bit of power over her she gave him; he knew that he gave her power over him in return. Because, when they had both been on the run from darkness and demons and desperate "friends", he had not remained aloof. He had grown close, so close. Close enough to her that during those times he'd constantly think of her more than of his mission. Close enough for her touches on his shoulders, a casual lean, the 'overjoyed' embraces, kisses… close enough for them to mean something to him. Certainly long enough to feel guilt.
So, back to the future, where he is standing soaked to the bone over an undead city hunting a shadow that once was close to her un-heart. He dreads to think closer to her than himself, but that was probably a fact. A boy, hooded and wielding two keyblades surges forward from the stagnant darkness. Enemies are curling around him, but well-placed strikes send them back to non-existence.
The darker blade on his left hand is of more importance to Riku than the boy himself at this moment. Because he has seen that particular blade somewhere, and it is taking all of his will to remember the person who should be wielding it now.
A girl. Walks along twilit shores, and ice cream, and a red-haired man with the blonde boy which is still fighting. The girl. Walks along changing worlds, and schemes, and a white-tressed boy in a black coat who is (secretly?) enamored of the girl that is just out of his reach. The sound of the tide singing along the tears of rain and the raging of a boy that is also fighting to remember that one lone person.
Steps up a surface. It should have been impossible, but it doesn't matter to either of them. They fight, the dark keyblade now in Riku's hand. It feels familiar. The memory walks up to him as they duel, flickering in and out. A voice, female and liquid. To him, faint as it is, it is music and loud as a battle cry. For it is her voice. And with it, with her pleas and comfort and soft, caressing words, comes a name. A form. Xion, I've missed you so…
The battle continued. He won, as he was supposed to do. The keyblade did not immediately fade away (as its mistress had done, in light and ice). It remained solid in his longing grasp. With the lack of light and the scent of rain and blurry eyes… he could just imagine that it was her hand, rather than cold metal. And he wills himself to not forget. He can't do that to her, not to the puppet that made him dance to her dysfunctional tune. He wills Sora, silently, to wake up and save the world like he is supposed to do. Maybe, when all is fixed again, she'll be back. Back like the tide.