Since AetherSX2 uses virtual Memory Cards (.ps2 or .bin files), you need to import the save correctly into your emulator's directory. 1. Download/Locate the Save File
Access the brutal end-game challenges without finishing the story.
Use the experimental Python script (not officially supported):
Go to App Settings > Advanced > Rebuild Memory Card Database . This forces AetherSX2 to index the exclusive file's unique save blocks without erasing them.