NG+ carries over levels, items, and skills. Some players want to replay the story with overpowered teams from the start. A complete save file lets you do that without beating the game first.
Before diving into the "how-to," it is vital to understand the technical constraints of the Nintendo 3DS software architecture, as it dictates how save files are handled. project x zone 2 save file
Not all save files are equal. If you are searching for the ultimate Project X Zone 2 experience, look for these features: NG+ carries over levels, items, and skills
How to Recover Old Data Files from Citron Switch Emulator without Losing NG+ carries over levels