I have both a warrior and a mage. I have noticed most skills say they do X amount of damage plus extra on a critical. The windmill skill does not say this but it still does extra critical damage like all other skills in the game. I'm beginning to think this is a bug because it allows warriors multiple crits in a very short time span and makes it a very over powered skill. Somebody please correct me if I'm interpreting the verbiage of skills incorrectly but I don't t believe windmill was ever intended to do crits.