You guys should purchase KH2FM+, and fight Data Matches. You'll soon come to appreciate Reflega over that crappy Aero.
The name's Josh, nice to meet y'all. I look forward to making new friends and stuff. You can call me Marly if you want, that's what everyone else calls me.
If Marluxia won against Sora...(assuming that was the question, I don't feel like looking) He'd avoid killing him. He would force Namine (by some sort of painful action) to collapse his heart, and rebuild it as he wished. Then with Sora completely enslaved to Namine, and thus to Marluxia, he'd use the Keyblade Master to destroy Xemnas and his whores. But since Marluxia wouldn't really have an Organization because Larxene is dead, then....he'd have to find some strong nobodies to fill the ranks. And we'd have a very lame game on our hands.
Didn't offend me one bit. Of course, there's little Marluxia fanboys that will probably flame you sooner or later.