Inaccurate?

Clinging Shadow Strike

(Tome of Battle: The Book of Nine Swords, p. 76)

Shadow Hand (Strike)
Level: Swordsage 1,
Components:
Casting Time: 1 standard action
Range: Melee attack
Target: One creature
Saving Throw: Fortitude partial

Your weapon transforms into solid darkness. When it strikes home, it discharges in a swirling orb of shadow that engulfs your foe?s eyes.

As part of this maneuver, you make a single melee attack. If it hits, you deal an extra 1d6 points of damage, and your opponent must make a successful Fortitude save (DC 11 + your Wis modifier) or suffer a 20% miss chance on all melee and ranged attacks for 1 round. A successful save negates the miss chance, but not the extra damage.

This maneuver is a supernatural ability.