I hope this works. I came up with the idea a few weeks ago, but… well, here's the first chapter.

Korra, Mako, and Bolin were practicing in the compound. Rejuvenated from the vision with Aang and the other past Avatars, Korra realized her bending was stronger than ever. She smiled when the boys glared at her enviously.

"Kya?" Katara inquired, stepping out of her little house. The Healer's daughter jumped down from her Sky Bison, smiling at her family. "I didn't know you were coming."

"I heard the Avatar was down here again and figured it would be a good time to visit. Bumi and Iroh are doing a fantastic job repairing Republic City, Tenzin." She grinned wickedly at her brother's horrified expression. "However, I didn't come here just to visit. I wanted a few people to meet Korra."

Korra glanced up at the Wind Buffalo again and noticed for the first time two girls sitting on it bareback. She felt something stir inside her. "You adopted them, didn't you?" she asked, remembering what Katara had told her.

"In a sense," the eldest answered for Kya. "I'm Astraea, and this is my sister Yue."

Bolin tilted his head slightly. "Are you both Waterbenders, too?"

"No," Astraea replied with a grin.

Yue shrugged. "Well, not entirely," she chimed in. "I am. And a Bloodbender." Pride shone in her eyes, along with something else.

"Don't be modest, Yue." Astraea leaped down from the bison with the grace of an Airbender. From her expression, she had the personality of a Firebender. Her gold eyes rivaled her sister's silver. Korra examined Yue more closely and realized that along with being a Water- and Bloodbender, she had the stature of an Earthbender. If that was even possible, the two were like halves of the Avatar. "If you're wondering, Korra, all your guesses are right."

Her jaw dropped. "How?" she exclaimed.

"Not sure. We were born like this." Astraea grinned at Mako and Bolin, who were both stunned. "I'm a Firebender, Airbender, and lightning and energy. Together we can cloud-bend and sand-bend."

"I'm a Waterbender, Earthbender, Bloodbender, and Metalbender," Yue continued. "If it's any indication, we have almost opposite personalities."

Kya turned to Katara. "I would have told you, Mother, but I was afraid of exposing them before they were ready. Republic City is slowly fixing itself, and I think it's time for the girls to help the Avatar as the Moon Spirit told me they should."

"Yue," Katara remarked fondly. "Sokka loved her first. I'm glad he found Suki. You said you saw Bumi and Iroh? How are they?"

"I think Iroh is kind of cute," Asami whispered to the newcomers. She had joined the group in time to hear their story and wondered if they really could bend so much.

Astraea glared at her. "If you don't believe us, just say so. Not only can we bend, but we can do it psychically." On cue, a gust of wind blew toward the rich girl and messed up her hair. Asami held Astraea's blazing eyes with a challenge of her own before turning away. "The first Yue, like Kya said, warned her that we would have to help you, Korra. We can teach you all we know, but I'm not sure if you'll be able to do everything we can. You're already quite powerful enough." She fixed her glare on Bolin. "Remember I can hear your thoughts, Bo. Energy, remember? I'll be watching you." Yue blinked apologetically at her sister's protectiveness.

"Wait," Mako interrupted. "Did you say that Kya sort of adopted you? What happened to your parents?"

Yue turned shy all of a sudden; Astraea stepped in front of her as if she could shield her sister from the memory. Sadness crept into her indignant gaze. "They were killed. Yue was five, and I was seven. We lasted three years on our own before Kya took us in." Anger replaced her grief. "I would do anything to protect her, as I'm sure you noticed. We taught ourselves our bending when we noticed we were different."

"I'm so sorry," Korra began.

Astraea shook her head. "Don't be. Things happen. I know these Probender bros have nearly the same story as us. By the way, great job in the tournament. All of you." She wanted to get off the subject fast, seeing the state Yue had locked herself in.

"Why don't I show you to Beifong? She's an awesome Metalbender." Bolin looked at Yue pleadingly, as if he suddenly wanted to protect her, too. Astraea knew that it just came with her personality. "Maybe she can show you something you don't know."

Yue glanced at her older sister, who nodded encouragingly. Mako and Astraea both watched their siblings go. "If he can help her forget, it might be for the best. I know it took a lot for him to forget about our parents." Mako met Astraea's gaze sympathetically.

"Korra!" Tenzin called. "We should get some Airbending practice in while we can."

"Coming!" she responded. The young Avatar turned to Astraea. "Want to practice together?" she offered. "Later we can work on Firebending, too. I know Mako loves new opponents."

Surprised at her kindness, Astraea gazed in the direction of where Yue went. "It'll be okay," Mako assured her. "Bolin doesn't hurt anything or anyone. I'd like to see what you can do, anyway." Up against me – the words were unspoken, but Astraea felt the flame of a challenge spark inside her. Unlike Asami, who she barely trusted for whatever reason, she knew that she could believe the Fire Ferret team.

"Sure," she accepted after a moment's hesitation. "Lead the way."

Sorry, my first chapters never have much action. I'll try not to make the OC sisters Mary-Sue, but please tell me if they start to come off like it. I have a lot planned for this story, if I get readers, anyway. Otherwise, this is going nowhere. Stick around and review, and I'll update as often as I can!