One Piece Chapter 33, page 6-7: The Silent Man

Terrified, Sham and Buchi spin around, crying, "He's behind us?!" but Kuro has already vanished again. "Huh? Dis... disappeared?!" they stammer, looking around wildly. Suddenly, with a heavy "DON!" sound, Kuro places his long, clawed hands on both of their shoulders. "You're right..." Kuro whispers directly into their ears, "I really don't feel too active." The two brothers scream in absolute panic: "WAH!!" "AH!!

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.