Copy and paste the downloaded system_data.bin or the entire save_data folder into this directory, overwriting existing files.
The most common way to "unlock all characters" instantly on a repack is to import a 100% save file . This replaces your local progress with a file that already has every fighter, stage, and often all spirits unlocked. How to Install : super smash bros ultimate unlock all characters yuzu repack
If you prefer to "earn" the characters but want to skip the 10-minute cooldown between encounters, you can use the trick. How to Unlock All Characters in Super Smash Bros. Ultimate Copy and paste the downloaded system_data