Basq doesn't exist. He occupies a point in space--a single X,Y,Z point in the Cartesian plane, but he's not made of anything. People looking at him see whatever they want to see. Or what he wants you to see. Usually a mix. Just the same, he cannot be hurt swords or arrows. Only things that deal damage to an area (fireballs, gases) can damage him. Or weapons that can cut through an infinitely small point.
A supposedly empty desert on the far side of the mountains has started growing. No one knows why. At the center of the desert lies a tall rock outcropping, hundreds of feet tall. Dust storms shroud the outcropping constantly, except for one night a year.