Risotto Nero

His stand is named Metallica, Metallica appears in the form of hundreds of tiny bodies, each resembling a small metal strip with vestigial arms, one or two scars, and featureless faces. Metallica is normally bound to Nero's blood, from which it can project magnetic auras. These auras allow Nero to reshape blood into any form by manipulation of the iron in hemoglobin. More specifically, he can manifest such sharp and deadly objects as razor blades, nails, and scissors directly inside his foe (apparently from memory, since the razor blades come with brand label etchings), and manipulate his own blood to create iron stitchings for any wounds he receives.

One of Metallica's most dangerous qualities is that even if its target isn't killed by being slashed and pierced by the created objects, the immense iron deficit created in the victim's blood will probably be fatal in and of itself.