Here's how Lee described the character in a text feature for Mystic Comics #6, back in August of 1941.
Captain America may be the most famous Marvel Comics' World War II era superhero, but he wasn't the only one. While the Sentinel of Liberty and fellow heroes like the Human Torch and the Sub-Mariner fought the Axis Powers on the frontlines, Kevin "Keen" Marlow, AKA The Destroyer, attacked the Nazi menace from behind enemy lines.
Writer Robert Kirkman and artist Cory Walker reintroduce the character to the world in the pages of a five issue "Destroyer MAX" mini-series from Marvel Comics' MAX imprint.