Conrad Stauffer
Conrad Stauffer was a Waffen SS officer who prior to World War II, was sent to America with Baron Ikito to obtain Frank Raymond's invisibility formula. He failed, and then when the war broke out Stauffer returned to Germany to act as head of the SS, not suspecting that Raymond had in fact volunteered to use his formula to become an invisible spy for the American government. While he was away in America, Karl Heiser attempted to steal his job as head of the SS, and Stauffer got his revenge by having Heiser arrested and executed by firing squad.
Heiser escaped, however, with the help of the invisible Raymond after telling him of the Nazis' audacious plan to attack New York with a fleet of bombers. After instructing two of his officers to shoot Heiser on site he went to the Japanese embassy where Baron Ikito, having doublecrossed Stauffer, had the invisible agent held hostage. A fight broke out between the two groups of Axis agents, during which Raymond escaped with the help of Maria Sorenson. Stauffer was then killed by Ikito, who stabbed him to death before taking his own life.