Nothing is known of Charles Karnaj before he was a petty criminal operating in Gotham City on Earth-Two.  There he was contacted by crime lord Edgar Stenville, who offered him a position as a gun-for-hire in his vendetta against lawyer Arthur Cranston.  He outfitted Karnaj with an extensive array of personal weaponry, which combined with Karnaj's considerable physical prowess turned him into adversary worthy of Gotham's strongest protectors.  Taking the code-name Karnage, he tracked the Huntress after her rescue of Harry Sims from an kidnapping attempt.  Catching her off-guard, Karnage launches a brutal assault.  Initial resistant, the Huntress eventually flees.  While failing to kill his quarry, the exultant Karnage reports back to Stenville that he has scored first blood.  Stenville instructs him to attack Cranston directly and that Huntress will come to him.

The following day, Karnage breaks through a window into the library of the Cranston law firm.  There he encounters Helena Wayne and Charles Bullock, who he promptly routes.  As Helena drags Bullock to safety, Karnage tears through office seeking Cranston.  Helena uses the respite to change into her Huntress uniform but Karnage is long gone, finding that Cranston was not in the office that day.  That evening, the Huntress surprises Stenville in his bed and extracts a connection to Karnage but causing the crime lord to faint in fear.  Following his lead, the Huntress finds Karnage's in his home and while he quickly attempts to fully arm himself, the Huntress takes the offensive.   The two battle across the room but ultimately, the Huntress prevails and Karnage is bound up for the arrival of the police (Wonder Woman #286-287).

 While quickly defeated, the actions of Karnage had two important consequences:  they helped convinced Charles Bullock to adopt the identity of Blackwing and helped Stenville deduce that Helena Wayne and the Huntress were one in the same.  The later activities of Karnage on Earth-Two have not been recorded.