What this game-specific editor changes
Transfer a verified Sekiro PC S0000.sl2 save to another Steam account by changing only the documented Steam account identifier and rebuilding the affected slot/settings MD5 values.
Verified input boundary
The file must be exactly 0xA603B0 bytes, begin with the BND4 header, contain a valid settings Steam64 value, and pass all ten slot MD5 checks plus the settings MD5 before editing.
What is deliberately not claimed
No stats, inventory, character-slot cloning, checksum repair from an invalid base, console format, encrypted FromSoftware format, or arbitrary Steam64 scanning is claimed.
Output
A separate .sl2 copy with the selected 32-bit Steam account ID reconstructed into Steam64, written only to used slots and settings, with affected MD5 values rebuilt.
Instructions
Close the game, back up S0000.sl2, select it locally, confirm the used-slot count/account ID, enter the destination Steam account ID, and keep the original until the copy loads.
Verification
Verified with two deterministic 0xA603B0 fixtures, native-crypto differential MD5 checks, corruption rejection, exact used-slot writes, original immutability, and post-write reopen.