These cruel customers' cunning makes them a hazard to those whom they meet. Conditioned to be the pinnacle of human physical perfection, each has a tactical mind nearly unmatched by their peers
Slade Wilson was a military man treated with chemicals that granted him access to mental capacities helping him unlock his hidden potential. Becoming an agent-for-hire, Deathstroke the Terminator fullfilled the contracted of his deceased son to defeat the Earth-One Teen Titans including Wonder Girl. While coming close, he never quite succeeded.
Black Assassin was an agent for Germany during the early days of World War II who first tangled with the American superhero known as Steel, and several months later reemerged to face members of the All-Star Squadron, once more facing and again begin vanquished by Steel who had pursued his old adversary.