I've been messing around with Shuffle since about this time yesterday in order to try and get the Japanese voices working in the English version of the game. I've found out that the MDTs contain the voice samples and have successfully brought most of them over, but one issue remains - ADXVOICE.mdt. This contains menu voices of Lumina, and board voices of Lumina, Void, and Eggman, along with a jingle that plays at the beginning of each board. When this file is replaced with its Japanese equivalent, the game hangs upon trying to load any board and I'm not quite sure why. I would try to replace the files within the MDT manually, but as far as I know nobody has made any sort of tool to repack them and I'm nowhere near experienced enough to do something like that.
It looks like there's some dependencies with ADXVOICE.MDT (or hard coded offsets). The hanging is likely caused by the game having troubles with the jingle that plays at the beginning of each board being in a different spot as the exact same file inside the archive ends up being at the wrong offset between the Western and Japanese versions. You'll have to swap subprogs and any dependencies with it. It's likely "ONES.BIN" you may just need to change. It should be noted it's a guess on my part as I haven't tested it out myself.
