The Indigo Bomb belongs to the illegal Majel set. It is a modified version of the Freeze Bomb, but the blast size is much larger in width and height, also providing longer immobilization. It is very easy to freeze and then inflict heavy damage on your opponent with another weapon.
Use just as you would with the Freeze Bomb. Just make sure you aren't above the bomb when it detonates. Because the bomb automatically aims directly at the foe, it's very easy to force the enemy to either side. Take advantage of that fact with flanking weapons.
Some prefer to use the Indigo Bomb like the Wall Bomb, in that it is used purely to serve as a blocker off to one side.
Dodge either left or right, but try to make your movements unpredictable.