X999

X999 was a mysterious warrior who guarded a bridge in the Trial Dungeon outside Toushin City. Their name changed over time, marking their growing collection of swords taken from defeated opponents. While initially disinterested in Custom, they may have simply been saving him for last: they ultimately challenged Custom for his 1000th sword, and was defeated.

Trivia

 * X999 is based on the legend of Benkei, who also collected swords before being defeated in the duel for his thousandth.
 * Despite only appearing in the mid-to-late-game, X999's image is right at the front of Toushin Toshi's image library, just after the images of Toushin City and of Dogi Magi from the introductory battle. He appears immediately after the combat GUI, which suggests the developers knew he would appear outside the GUI's "frame" from the earliest stages of development, and had him prepared as soon as the frame was ready.