"I need to ask you something." Xiria got close to Riku, her eyes locked on his. He looked like he was lost in his own world, thinking about something completely different. "What is it?" Riku's voice was low. Xiria tried to find the words to make her question simple. "How do I make it go away?" She kept her ears low and kept her eyes closed. Riku's face became confused. "What do you mean?" Xiria opened her eyes and said everything that was on her mind. "All this darkness! I have done nothing to become what I am. I never wanted any of this! Taking peoples hearts for someone elses benefit doesn't please me. I just want to make it go all away!" Riku looked down at her. He seemed troubled and sounded annoyed. "Why are you asking me about this?" He spat. Xiria looked at his face with big eyes. She spoke softly, "Because you're the only one that I know who has been through all the darkness and back to the light. Please." Riku stepped back and turned around, walking away from her. "Can't help you." He said coldly. "Please! I can't even get the on I love to love me back because of what we are." She held herself and got to her knees, leaning over the floor. Her stomach turned and she felt she was going to faint. "What are we known for?" Riku stopped and turned around to watch Xiria. He wanted to help her but couldn't. He wanted Xiria to see what happened to him when he followed with the darkness. "You're a nobody. You have no feelings. You don't feel love, remorse, or sorrow. Nothing." Riku explained. Xiria caved in, tears edging the bottom of her eyes.
Riku thinks that because this takes place when Xiria is sided with Xemnas and the original Organization. She was working as the organization's little spy to watch over Max, Lixcea and Rexeal. That's what he means by following the darkness.