Unlike modern cloud-based games, MHP3rd stores everything locally. If you lose this folder, you lose your Hand of Atalanta, your full Narga armor, and your 30+ minute solo Alatreon clear. No cloud backup exists natively.
While you cannot "transfer" a full character from Monster Hunter Freedom Unite (MHP2G) , having a save file from that game on your memory card allows you to import specific rewards, such as Mufuroro Felyne armor and special Guild Card awards. monster hunter portable 3rd save data
Before manipulating any files, you need to understand what you are dealing with. Unlike modern cloud-based games