Due to the length and sharpness of the blades, one swing can inflict multiple aggravating wounds and cut through walls and rocks. However, they may not be durable enough, as Luffy managed to snap the right claw. As a reference to remembering how to kill, Kuro pushes his glasses up with his palm, in order not to scratch his face with his claws.
Kuro primarily uses these giant claws in conjuncture with his superhuman speed to strike his opponents with such swiftness that they will not know what struck them until it is too late; he can reportedly kill 50 highly skilled assassins before they notice his presence.
Though Kuro's raw speed — which is roughly the same as that of CP9'sSoru technique — and long claws makes him a deadly fighter, his weakness lies in his inability to see clearly while running, causing him to strike anything his claws randomly connect with, whether it be an enemy, the surroundings, or his subordinates.
Shakushi (杓死,Shakushi?, literally meaning "Death Scoop"): Kuro's ultimate technique. A fearsome attack that utilizes Kuro's Nuki Ashi to the fullest, moving at a speed of 100 meters in 4-5 seconds, allowing him to sweep a large area, killing anything his claws connect with at random, including his own crew. He initiates this move by swaying back and forth sideways in a fluid manner — this is necessary in order to enter the "trance" needed to perform the move. The order in which he inflicts his attacks are so random that they range from mediocre scratches to fatal evisceration to both friend and foe alike. He moves so fast even he does not know what he's attacking, and only stops when tired out (or when someone can catch and physically stop him, as Luffy did). In the anime this move has the side-effect of generating purple clouds of smoke to rise from the ground as Kuro moves at his topmost speed. It is said that he killed many of his own crewmates in the past with this technique. In Unlimited Cruise, Kuro uses this attack to focusing onto his opponent with multiple strikes, rather than a widespread carnage. In the Funimation dub, 4kids dub, and Viz manga, this attack is called "Out of The Bag Attack"
The name of this attack comes from the Japanese phrase "neko mo shakushi mo" (猫もしゃくしも,neko mo shakushi mo?, literally meaning "even cats and rice ladles"), which is a Japanese figure of speech, meant to mean "absolutely everything", reflected in the fact that this attack indeed attacks "absolutely everything". The word "Shakushi" is homonym with "Rice Ladle". It's also a pun of the Japanese word, Sakushi which means schemer, hence Kuro's personality.