Some of the villains actually are built around using blocking and dodging. Besides obvious people like ExDeath, both Sephiroth and Jecht actually have block incorporated into their actual move set (Sephy even has a HP attack that begins as a block and then moves into the attack, much like WoL) while Kuja and Ultimecia's whole fighting strategies are about using their Auto-glide to easily dodge and counterattack opponent. The villains actually use a much more diverse and creative fighting styles compared to the heroes. Its one of the reasons why they are more challenging to use cause many of them are radically different from the heroes.