Here the two voice files from the Japanese version of Trails in the Sky SC, I replaced the files from my English GOG copy of this game and so far it works fine, in Options I can now select Japanese as a new voice option and have Japanese voices in the battles.
I didn't beat the whole game yet (obviously since it just came out) but the same method did work just fine for FC, so I have high hopes it will also do for SC.
Thanks to Falcom for making these wonderful games and to Xseed for their great localizations, just PLEEEEEEEASE include the Japanese voices in the future!!!