ECHO Change Drive letter and path to game for this to work.
for /r "D:\path_to_game\Monochrome.Mobius.Rights.and.Wrongs.Forgotten\MonochromeMobius Rights and Wrongs Forgotten_Data\StreamingAssets\Windows\asset_bundle_variant" %%i in (*.en) do ECHO ren "%%i" "%%~ni.en.bak"
for /r "D:\path_to_game\Monochrome.Mobius.Rights.and.Wrongs.Forgotten\MonochromeMobius Rights and Wrongs Forgotten_Data\StreamingAssets\Windows\asset_bundle_variant" %%i in (*.ja) do ECHO ren "%%i" "%%~ni.en"
pause