The dimension restricts movement (which as you have pointed out, it's something he has already shown some resistance to) but is that really the "only" counter?the only other counter I can think of is this ability to move which he has shown to counter being restricted.
Before Erza overwhelmed the dimension, she could already move simply by using her usual magic for moving her weapons/armor around, meaning magic isn't restricted at all, nor are any of God Serena's long-range abilities, of which he has plenty as a dragon slayer.