In Dissidia 012 Duodecim: You need to equip accessories & armor that increase drop rate, maybe even buy Item Rate Drop up in the PP catalog, & after you have that increase your luck stat, it helps a lot with this. Then you need to choose a target character & base armor. Save that target character on a friend card and then export it. Start battling this card as many times as it takes to get the armor stats you want. Good luck!