Goblas are like upgraded versions of the Colbas found in first Grand Staff, but DAMN have they been upgraded. With more than three times the amount of health, they stick in the battle a fair bit longer. They like to use Break Hit so that they can attack both your front and back row characters effectively. And if that's not enough, their elemental defense is quite high. Groundus works well, but don't even bother with Grounda. If you don't have Aquarus, Forcea and physical attacks are the best way to deal with them.