One Piece Chapter 33, page 7: The Silent Man

Kuro holds his deadly claws right at the necks of the trembling Nyaban Brothers. He declares, "You're also right, that I'm no longer your captain... I am only the 'client' in this plan!! A client who will kill if the plan fails!!" Sham and Buchi can only shudder, whispering, "So... so fast...!!" Nami watches in disbelief, realizing that the Nyaban Brothers, who easily fought Zoro, are like helpless babies in Kuro's hands. Jango explains to the onlookers that Kuro's "Silent Step" is a soundless movement technique so perfect that he could silently assassinate fifty men, making escape from his plans impossible.