As an action, you can make a weapon attack and throw sand into the eyes of a creature that you can touch or see within 2 meters. You must have sand in your hand to throw. Add the stamina die to the attack’s damage (add half if you miss by 4 or less). On a hit, the creature must succeed on a Fortitude saving throw or it is blinded until the end of its next turn.
You can augment this maneuver with the following options, expending stamina dice for each option.
You can increase the damage for each additional stamina die expended.
You can expend 2 additional stamina die so the creature is blinded for 1 minute/stamina die. At the end of each of its turns, a blinded creature can repeat the saving throw, ending the effect on itself on a success.