Kingdom Hearts: What Kind of Curse Is That

Sora's a Heartless, Xion's alive, and Roxas is with her, along with Kairi and Riku. On their journey to get Sora back. Xion x Roxas, and maybe some one-sided Riku x Xion, and some Sora x Kairi, cuz we know they love each other. The main enemy is an OC. Derp I don't know what else to say, I'm horrible at making summaries, so just read, okay?