- "A skilled shadow killer can vanish from sight."
Shadow killer was a Nightsisters rank and specialization.
A shadow killer was an assassin from Dathomir. They carried weapons that were silent and easy to conceal, such as daggers and darts dripped in poison. They also wore black wraps to help them blend in with the dark. Shamans of the Nightsisters such as Talzin could summon a mist that allowed these killers to walk midway between the physical realm and the spirit realm.
In 21 BBY, Clan Mother Talzin allowed Asajj Ventress to use the Shadow Killers' mist so that she could have revenge against her former master, Count Dooku, with the help of two of the coven's finest warriors, Karis and Naa'leth. She also provided Ventress with the poisoned dart of the assassins.
According to Galactic Emperor Palpatine, the stealth skills of the shadow killers could easily rival those of the Defels agents. This is why the Emperor ordered the Imperial Security Bureau to conscript from the Nightsisters assassins some time after 19 BBY.