Moody and Aurors Arrive
Alastor arrived with the first group of Aurors to make it on scene -- mostly those already on the night shift and not needing to be roused by the general call. It took only moments to direct his men out into the area with instructions to engage if necessary, but to focus on protecting the civilians and getting those fires out. They had appeared right in front of one of the burning houses and he took two men with him to make sure the family was out and to put out the fire.
By habit, he had cast a shield before they moved out, which was the only reason the flash of violent purple light in his periphery didn't hit him. Spinning in the direction it had come from, he watched it rebound and strike the caster not ten feet away. For a first field test of those shields Potter had gotten from Snape, he liked it. Not waiting to see what the writhing ropes of light now wrapping around the caster would form into, he stunned and bound the man.
Before he moved to examine the dark spell that still lingered and take the man into custody, he looked around for any other threats, the two men accompanying him having gone around to the back of the building.