Quote Originally Posted by Skyblade View Post

A goodly number of the villains aren't the end-all final villains of their games. The developers specifically chose villains who weren't end-game bosses to avoid the villains with little to no character development, like Zemus/Zeromus, Yu-Yevon, and the others in that same group. They also tried to go with characters who had attachments to the main characters, yet were still important to the plot.
They chose Cloud of Darkness over Xande