Special Attacks refer to anything activated by the
button. This can include the basic Special Attacks that the characters can use on their own or the Special Kizuna Attacks that come from activating Kizuna Rush and then using it. Given that many of the Legend Diaries require you to kill the mission boss under this situation, you might get used to using it to finish them off, but this will also require you to clear several thousand grunts in the same way. This would probably be best done when conquering enemy territory, as they often gather in straight lines when you first enter.