With Signature Move you can disarm an opponent, Blind your opponent and Sweep him and stun him.
Disarming is a fight changer
Sweeping , knocks them down leaving them prone
Stunning can be a biggie if early in the round or for multiple rounds...but
Blinding seems to have nearly no effect or at the most a very minimal effect to the opponent .
I'm gonna do a little crying here...being that it is a Theatrics 3rd level offensive skill....Blind really needs to be matched up in effectiveness with Disarm, Stun and Sweep.

If you blind the fighter he should be pretty much unable to see your attack coming at him as well as being pretty shaky on defense...and IMO it should reduce his attacks too since he would be a bit out of sorts by not being able to see with sand in his eyes.

That's my rant for tonight.