There is only one primary English patch available for the original PSP version, and it has significant limitations compared to modern alternatives: The "Guren" Patch (Leaked Version)
Check the MD5 checksum of your patched file against the official release notes to ensure it is correct ( 3002BBF9862D9ADBAB4226C38EB35F49 for the 2025 port). Comparison with Other Platforms PC/Switch/PS4: Official English releases are available by NIS America