The first thing that Arad saw was a flash, and by the time he lifted his arms, the whole flew in front of him in the blink of an eye as both his arms shattered like old rotten wood. His body flew backward so fast that the air friction ignited him like a meteor, and he could already guess what hit him.
It wasn't a physical attack or a regular spell. It was a compressed wave of Mana, a force as solid as matter but much, much more powerful. It was similar to a shockwave, but instead of being made from compressed air, it was made out of Mana.
He didn't see which one of the twins cast the Mana shockwave. But he now thinks it was Rey who had her arm up. Those blue eyes, he must keep following them and expect more shockwave attacks like this one.
Sadly, before Arad could finish that thought, Ray was already upon him. Unlike all of his foes, she didn't swing a weapon, her fists, or even cast a spell.