Before proceeding, it's important to understand the legal and ethical context. Emulators themselves, such as RPCS3, are legal, but using them to play games you do not own is not. Demon's Souls is still copyrighted by Sony.
To get the absolute top performance out of the original Demon's Souls, certain configurations are highly recommended depending on how you play. On Original PS3 Hardware demon souls ps3 pkg top
Copy the Demon's Souls PKG file into the root directory or a folder named packages on your USB drive. Before proceeding, it's important to understand the legal