Very few characters with as much reach across different comics are as terrifying as Onomatopoeia. A serial killer who goes after any hero vigilante who doesn't actually have "powers" is a target for Ono. The terrifying part is that no one really knows why he does this as we never get a back story. Most villains get a back story at some point, but not Ono.
Kevin Smith is a fantastic comic book writer and this is one of his more outstanding works. Though not as well known, this Green Arrow run should be seen as something to read back through with the success of the Arrow TV show.
Writers - Kevin Smith
Pencilers - Phil Hester
Cover - Matt Wagner
Inkers - Ande Parks
Colorist - James Sinclair
Letterer - Sean Konot
Editors - Bob Schreck and Nachie Castro