Okay, I now have a KH OC. Her name is Kira (her name means "shine")
(or Princess Kira).
Kira is a princess that gets kidnapped after the events in KH2. Her father sends word through any means to any world that would listen. It reaches Destiny Island and Sora takes up the adventure. Kairi follows Sora and Riku comes along to make sure they don't get hurt. They find her and she has no memory of herself at all. They bring her back to her world but find out that she has to be restored.
Kira has a half-heart (half her heart went on a journey to find the one she loves in order to rescue him) and thus has no memories of herself. She carries a key that can become a sword or arrow. It gives her the ability to fly on it like a broom. She can borrow Sora's keyblade but only for a short time (about an hour).
She has a friend/BF named Sakuban (means "Last Night" named after one of my fav songs by Skillet ^_^!).