After accompanying S&J, Piven was brutally shot by bad guys and was promptly embraced by Smith and then staked by Magenta. However, Smith soon revived him and took him under his wing, teaching him the ways of vampire-dom (or at least his own idiosyncratic take on these).
Piven displays both strong gift of Presence, and a gluttonous appetite for blood. His preferred food is pretty and female, or other vampires…