Dissidia Final Fantasy: ghosts and ghost data?

Hi all, I bought Dissidia final fantasy a few days ago and I have played it for a while. I now have the warrior of light at level 50 being my highest level character. I am in need of Rosetta Stones for slots and it sure would help to have suggestions on good bravery booting items. I have been looking around online for ways to get these items, but all of them seem to require that you have beaten story mode, except a ghost battle. Which brings me to my question, how in the world do I use ghost data, and how would i make a rosetta stone with it? I am seriously confused to everything on here that says ghost on it. Any suggestions or help? Also, if any of you know the link to an item list website that will tell me accessories and items that will increase bravery and hp, that would be great. Thanks a bunch! :D