To get the "Destiny" item (requires no damage taken), just use Quick Save (F1) before fighting a general. If you get hit, quick load (F2). But honestly, if you download a full save data file, you won't need to do this at all. Just enable "Cheats" in the PPSSPP menu and load the ULUS10412.ini file.
: All story paths cleared, including the five new arenas added for the "Special" version. shin sangoku musou 5 special psp save data