In the context of a competitive fighting game, yes—you will have an unfair advantage if you bring maxed-out characters against a friend who just bought the game. However, for a solo player, using save data is considered a , not a cheat.

One major pitfall: . A Japanese save ( SLPS-25721 ) will not work with a North American ( SLUS-21878 ) or European ( SLES-55077 ) disc without hex editing. Tools like PS2 Save Builder can sometimes convert between regions, but character offsets may shift, leading to glitches (e.g., Naruto having Sasuke’s moveset).