X is Rui Ninomiya's computer A.I. and the one responsible for the day to day operations of GALAX when Rui is not around.
- X is named after Sosai X, the villainous head of Galactor from the original series.
- Despite the name, X's behavior in the series is the polar opposite of his counterpart and is a friendly ally of humans. The only thing that comes close to him being evil is when he was hacked by Berg Katse into thinking that Berg was Rui and obeyed his commands, albeit against his will.