Official
Mortal Shell 2 Save File Location
The exact PC folder can vary by storefront and build, so locate the active save by timestamp instead of copying a Mortal Shell 1 path. Steam confirms Cloud support for Mortal Shell II. [steam]
On Windows, save and quit, then search your user profile for recently modified folders named MortalShell2 or SaveGames. Verify the candidate by matching its modification time to your last save. Copy the entire folder while the game is closed, and keep Steam Cloud enabled unless you are deliberately restoring an older backup.
Never overwrite the only copy; restore from a duplicated backup folder.