Quote Originally Posted by Kawaii Ryűkishi
Quote Originally Posted by masamune1600
FFX-2 did not include anything called the Masamune.
Actually, Rikku wields Auron's Masamune from FFX when she becomes a Dark Knight.
Yes, the appearance is the same, but no name is actually attached. One could argue that the Caladbolg is also present, again without name. However, since the statistics and abilities of Dark Knight are completely identical for all three girls, one might assume that the Masamune is no different from the other swords seen used by a Dark Knight. It seems more likely to me that they simply reused the sword design, as it seems to fit the appearance of a Dark Knight.