My apologies, just being impatient. Every time I open the .SAV file with PKHeX it just says 'Invalid save file loaded. Aborting.' and nothing happens. Not sure if it's a japanese save file error or what.. It doesn't let me edit the .SAV file in ANY save editing software, but it does let me editing .BAK files.
With PokeGen I open the save file, select Japanese Diamond and it just closes instantly.