Well I think it might have something to do with Rinoa. There is no Rinoa in the game, she's not shown or mentioned... but Leon does have a red print of Rinoa's wing designs on his back. Maybe that's the way of showing that Rinoa does exist in his world, and that was a tribute to her? Maybe she was killed by the Heartless... though he didnt seem to broken up about it. I dunno.