Overt-Kill is a cyborg who makes his first appearance in Spawn Issue #6. He is hired by Tony Twist to kill Spawn.
Overt-Kill used to be known as Nicholas Rocca in Sicily. At age 13 he was already a thug running an extortion racket to local businesses and even offering himself as a leg breaker for the mob. Soon he became one and was hired by a mob boss named Luciano.
During a job he ended up killing the son of a rival mob boss and soon that mob boss called in favors from oil-rich Arabs and thus the Arabs got people to attack Rocca and the massacred him. However, he did survive and was rebuilt into a cyborg. He was soon sent to New York to attack Spawn after Tony Twist hired him to do so.
Overt-Kill nearly killed Spawn.(Spawn #6)
However, Spawn returned and attacked Overt-Kill where after learning information he decapitated Overt-Kill and threw his head away. (Spawn #7)
Overt-Kill would later return and hired by Jason Wynn to kill Terry Fitzgerald who he feared was going to learn about Al Simmons. Overt-Kill nearly killed Terry until Spawn came and fought him. Soon Detective Twitch Williams shoots him in the ear causing his circuits to go mad and decides to go get revenge on Badrock. (Spawn #8)
Overt-Kill would later be mentioned as when Tony Twist's boss ordered him to get back Overt-Kill but instead he just got Tremor.