As soon as she heard Erik's shout, Naeku blasted a nearby creature away with sand, then crouched low. At the same time, Erik leapt over and landed just in front of her with both hands raised. One hand was accompanied by an icy-white magic circle, the other by an icy-blue one.
The main reason Elora had taught him dual casting in the past was because he could use it to advance both his runes and glyphs at the same time, but that wasn't its only use. Though complex and cost-inefficient, it was times like these when Erik used it in combat.
The magic circles flashed, and the magic activated. Instantly, ice-maker created a large wedge of ice, and a thundersnow shield formed directly behind it. At the same time, the dragon lowered its head to the floor and gaped its maw. With a devastating roar, it blasted out a sea of fire, surging for Erik and Naeku.