While most of the Realm of Darkness would be trying to kill anything with a heart, the Dark Margin was, at the moment, singularly peaceful. A sun that was not a sun held still in the sky, and waves crashed on the shoreline. But sometimes, dark beings would try approaching the sand, so Aqua had made doubly sure to rid the area of as many as possible before Riku woke.
Him appearing from the sky was just about the most surprising thing that had happened in - months? Years? To see a person, a real person, with a heart and a body and a mind and everything, and for him to be someone she'd met?
"Now the only thing that can disturb the peace is us," she mused, aloud. She would have to warn him not to get desperate about anything, that usually attracted the darkness.
And then, suddenly, she saw him tossing and turning in the sand, as if he was fighting something. That makes sense. His heart is fractured.
"Are you awake?" she mused.
At this, Riku violently awoke, gasping as if coming from a nightmare.
His eyes narrowed as he saw her. "Who are you?"
She laughed, softly. "Don't you remember?" She bent down. "I'm sorry, I don't think I ever introduced myself. My name is Aqua."
"You …" Riku put his head in his hands, trying to remember the identity of the blue eyed woman standing next to him.
Sora, do you like Riku?
Of course I like him, he's my best friend!
Good. So then, if something happens, and Riku is about to get lost – or say, he starts wandering down a dark path alone – you make sure to stay with him and keep him safe. That's your job, Sora, and I'm counting on you to do it. Okay?
His eyes widened. "I met you on our island," he said, slowly. She had been from another world, just like that man - what was his name?
But at the moment, he knew that did not have time to reminisce. "Do you know how to get back? Do you know how to travel between worlds? Where are my friends?" By this last question Riku was upright and practically shouting at her; he remembered how he had left Sora and Kairi alone and unprotected, and hated himself for it.
Aqua looked away at the horizon. "I'm sorry. I've been stuck here for a long time. I don't know anything about the Realm of Light as it is now, or how to get there. And I don't know where your friends are."
Riku looked down. "So I'm stuck here too?"
"Yeah." She said. The waves crashed around them as they sat in silence.
Aqua considered Riku. Before he woke up, she had taken advantage of his weakened body and spirit, so she could look at his heart. He obviously could use a keyblade, but - something was blocking it. There was this untapped power inside of him, bottled up. And from that, darkness grew. His light was in a constant battle to contain it, and it always - barely - came out ahead.
That's what happens when you keep part of yourself bottled up, but why ... ?
Normally the amount of darkness in a heart didn't matter if someone had the potential to use the keyblade; usually it was strength of heart (resolve, willpower, ability to persevere against impossible odds, hope) that made someone able or unable to use it. But Riku's heart was certainly strong enough. He practically reeked with focus.
Why is he fighting his darkness? And why do I get the feeling that bad things would happen if he didn't?
Because it was possible that that wasn't his darkness. And if it was foreign ...
Well. Then he would really be in trouble; Riku's heart had become compartmentalized, and it would be frighteningly easy for him to be possessed.
Aqua's thoughts came back to her as Riku began to kick the sand into the air. "So much for seeing other worlds." he grumbled, breaking the silence.
"How did you get here?" Aqua asked.
"There was a storm outside, and it was going to tear apart a raft we built. The storm - I'd heard about darkness as a kid, but I always thought it was just a metaphor. And then it broke into my heart, but something's holding it back."
Aqua sighed, inwardly. Helping him would be tricky. One wrong move and his heart might be ripped out.
"Is it your light? That's holding the darkness back?" said Aqua.
"I don't know," said Riku. "All I know about this stuff comes from the stories our parents used to tell us as kids." And instinctual knowledge that he doesn't know how he knows, and the knowledge the darkness gave him of other worlds, and that voice that talked to him in his heart - but Riku wasn't going to tell Aqua that. He was still ashamed of it.
Then, suddenly, heartless appeared behind them.
Riku cursed. He didn't have a weapon - even his toy sword was lost. But before he could react further, fire and lightning came out of Aqua's hands, dancing around her until all of the heartless vanished.
"You would think," she said, when she was done, "that they would eventually learn." She sighed, then sat back down again.
"How about you? How did you get here?" asked Riku, once Aqua was properly seated.
"I sacrificed my keyblade and armor a long time ago, to protect my friends. Oh, yeah," she said, as Riku suddenly became very interested, "I used to be a keyblade master. Riku … on the day I met you, I saw that he had - that you had been given the ability to use a keyblade."
"Well, so much for that," said Riku, bitterly. "I tried to use it on my island, and it didn't work."
And here was the proverbial moment of truth. Aqua could teach him, and teaching him might be the only way in the foreseeable future for her to get back, but she had no idea how much it would cost him.
She thought of Terra, trapped by Xehanort, and Ven, whose body was in Castle Oblivion.
I need to help them.
Maybe it was the darkness that led her to this thought. At this point, she didn't care. For all she knew, Riku was a gift from the light; she couldn't escape the feeling that they could make a door, if they tried, and what a boon that would be. But why would the light send an innocent boy here, away from his friends, after the darkness destroyed his world? Into the Realm of Darkness, the most dangerous place she could think of?
I need to help him, too.
Finally, she spoke. "I could teach you how. I had - have - a friend with the same problem."
"What problem?" Riku said. "I'm not weak."
Aqua smiled inwardly. He really was just like Terra. "I'm not saying you are. But, in order to find your keyblade, you have to know how to seek out the light in your heart, and draw out its power. And I can help you with that."
"Wait. My keyblade? Isn't there only one?"
"No, actually. Normally keyblades are passed along. That's why there are so few - too many people died before they could pass them on in the Keyblade War. You've heard of that, right?"
"Yeah. In stories. People wanted to keep the light for themselves, right?"
"And thus, darkness was born. You've got it." Aqua paused. "So? Do you want my help?"
Riku considered the offer. "Why are you helping me do this?"
"I've been stuck here for so long that it's nice to see someone else who's not a ... " What did Yen Sid call those things again? They've gone through so many names.
"Heartless." Riku immediately supplied. Wait, what? he thought. How do I know that?
"A Heartless, then." said Aqua. "And, there's another reason: we can't go back without a keyblade. But maybe, once you can summon it, you can make a path."
Riku took only a second to decide. He needed any help he could get to be stronger. "I accept," he said, resolved. "Teach me how to use a keyblade."