Every duelist from Gen 1 to Gen 5 is unlocked as a partner.
If you want to unlock things yourself but need a nudge, CWCheat codes are your friend. These can be enabled directly within PPSSPP and are a powerful alternative to a downloaded save. The most popular codes include: Every duelist from Gen 1 to Gen 5 is unlocked as a partner
The easiest method for most players is to find the to English. Several sources offer the "Yu-Gi-Oh! ARC-V Tag Force Special (English Patched) PSP ISO" for use on PSP consoles or the PPSSPP emulator. Look for version 2.1 , as it is the most complete and stable release. Every duelist from Gen 1 to Gen 5 is unlocked as a partner