Unseen Weapon (Su): As a standard action, you can wrap any melee weapon you wield in a layer of shifting shadows. This causes the weapon to darken, become less distinct, and leave a trail of shadow behind it as it moves. Your weapon must be in hand and ready to use for you to draw upon this power. You can dismiss the effect with a free action; dropping or sheathing the weapon also ends the effect.

Once per day per shadowblade level, you can activate one of the powers of your unseen weapon as a swift action. At 1st level, you have the power to make an unerring strike (see below). As you gain levels in the class, you acquire additional choices when activating your unseen weapon, as indicated on Table 2—6. When you activate your unseen weapon, choose one of the available abilities. Multiple uses of the same ability do not stack on a single attack.

Unerring Strike: Your next melee attack ignores any miss chance because of concealment or total concealment. You gain this choice at 1st level.

Unexpected Strike: Your opponent is denied its Dexterity bonus against your next melee attack. You gain this ability at 3rd level.

Ephemeral Weapon: Your next melee attack deals an extra 2d6 points of damage, as extraplanar darkness momentarily replaces portions of your opponent's body. You gain this choice at 5th level.

Shadowy Strike: Your next melee attack is resolved as a melee touch attack, ignoring armor and natural armor. You gain this ability at 7th level.

Far Shadow: Your melee reach is increased by 10 feet for 1 round. You gain this choice at 9th level.

At 10th level, you can use your unseen weapon abilities as a free action, though you are still limited to one use per day per class level.

Shadow and Stealth (Su): Beginning at 2nd level, the shadows that engulf your unseen weapon cover you as well, granting you a circumstance bonus equal to half your class level (round down) on Hide and Move Silently checks.

Sudden Strike (Ex): Beginning at 2nd level, if you can catch an opponent when she is unable to defend herself effectively from your attack, you can strike a vital spot for extra damage. Whenever your target is denied a dexterity bonus to Armor Class (whether the target actually has a Dexterity bonus or not), you deal an extra 1d6 points of damage with your attack. This extra damage increases by 1d6 for every two levels thereafter. You can't use sudden strike when flanking an opponent unless that opponent is denied its Dexterity bonus to AC. Ranged attacks can count as sudden strike attacks only if the target is within 30 feet.

Sudden strike functions identically to sneak attack in all other respects. The extra damage from sudden strike stacks with the extra damage from sneak attack whenever both would apply to the same target. It also stacks with the ephemeral weapon ability of the unseen weapon class feature.

Shadow Vision (Su): Beginning at 3rd level, you are able to see clearly in shadowy illumination. Thus, you can see up to 40 feet clearly in the illumination provided by a torch (which gives off bright illumination in a 20-foot radius and shadowy illumination for 40 feet beyond that), or twice that if you have low-light vision.

See in Darkness (Su): At 7th level, you can see perfectly in darkness of any kind, even that created by a deeper darkness spell.