"Just a bit of wind!"
Gwath charges blindly forward (25 feet for Move Action), caught up in arrogance, and swings his blade at the elusive entity.
Attack: 1d20 + 6 ⇒ (3) + 6 = 9
Damage: 2d4 + 6 ⇒ (1, 2) + 6 = 9
... And he starts to realize what a bit of wind really means.