A/N) F!Xenon = Ceryn, because two Xenons are going to get confusing. Enjoy.

:):o Promise o:(:

"Where're you going, Xenon?"

Xenon turned around guiltily, Claudine staring at him before shifting his gaze to the speaker. Ceryn watched as Claudine opened her mouth as if to speak, but Xenon stopped her quickly. She frowned, stepping backwards. "Where're you going?" she repeated, slightly more forcefully. They couldn't possibly lock into a staring contest - neither of them needed to blink - so their tone was the only way for either of them to show dominance over the other.

That was why she was shocked when Xenon drew her into an embrace, whispering "I'm sorry" to her. She blinked, slightly confused, but didn't move, simply glaring at him while her gaze faltered. "I need... I need to leave," Xenon said softly.

"Where?" Ceryn asked, slightly concerned for her who she had considered her brother. Xenon sighed.

"I can't tell you that," he said with a resolute and slightly urgent tone to his voice. "I just need you to stay here and protect the Resistance. You know the Black Wings, don't you?" Ceryn nodded at the question in response. "They might attack at any moment, and I want you to protect them. I know the others can protect themselves, but the trainees might not be able to."

"When will you come back, though?" Ceryn asked quietly, frightened of the answer. Xenon hesitated, drawing back as he bit his lip as he thought how to respond. 'Please give a positive response,' she thought to herself, but didn't voice it out.

"...Soon," Xenon responded after a few long seconds. "I'll be back soon. I promise you that," he smiled at her before walking back towards Claudine. "Protect the Resistance for me, okay?"

"...Okay," she said slowly. "You promise. You can't break it now," she said as she headed off. Better to train some more if she needed to protect an entire organization. She couldn't fail that certain mission if it was given to her by her brother.

He left that night, along with Aidan and Luka. She never knew where he went, as Claudine wouldn't tell her. She soon figured out what had happened, though, when she heard that the Heroes and the Cygnus Knights had left as well.

Her brother had went to fight the Black Magician without her. She kept quiet though, and did her mission with excruciating carefulness. No Black Wing got into the base, although she got hit several times from her back, due to no one watching out for her. She kept looking around, distracted, for her brother who wasn't there.

Eventually, Luka and Aidan returned, Aidan with a beat-up mechanic robot and Luka with his clothes ripped into shreds at certain parts. "Where's Xenon?" she asked, as Aidan quickly set to work repairing her.

Aidan frowned, but didn't answer, and Luka left. Ceryn immediately grew worried, but dismissed it. Xenon promised he would return. He had to. He promised, so he will. He wouldn't break his promise that easily.

But even then, inside, she knew how xeneroids could be destroyed. They would be smashed into pieces. They wouldn't be recognizable in the end. But she shook it off. Xenon promised he would return.

He would return, with a 'sorry' for taking so long, maybe. She waited, every day, ignoring the worried glances Aidan and Luka had shot towards her before they looked at each other. Xenon would return. He had to.

But he never, ever did.