To play the "uncensored" version of Manhunt 2 on a PSP, you typically need a modded console to run a patched ISO or a specific plugin that removes the "blur" filters from executions.
Let’s address the elephant in the room. Searching for "Manhunt 2 Uncensored ISO for PSP" almost exclusively leads to ROM sites, torrent trackers, and file lockers. Manhunt 2 -USA- -Uncensored- ISO for PSP
Your console must be running Custom Firmware (CFW) like PRO or ME. To play the "uncensored" version of Manhunt 2