Oh, as an additional note, the main-story mission "Rumors Abound" from FFTA2 specifically calls them the "Dozen-and-One Knights of Aisen". Perhaps just a fancy way of calling them the Aisen 13, or perhaps an indication that there was one somehow different from the others? Which would give us the twelve Zodiac Braves and a thirteenth, who carried Serpentarius, the unique symbol.

And thanks a lot for the interest, guys.