Assuming you haven't been cursed, if you get Aura, you can cast that on someone too to increase the chance for the limit option to appear instead of the normal attack option. Although I tend to avoid casting Aura since I much prefer to keep it junctioned instead Also, you can keep hitting triangle in battle if the character's menu doesn't have the limit option (or whatever button you set to change character) and they already have low HP, and you basically get another chance at it appearing again