Disambiguation: Richard Spencer, from Espionage [Quality]
First published in: 1938
Black X [Richard Spencer] first appeared in Feature Funnies (Quality Comics, 1937 series) #13 (October 1938). The character is renamed Black Ace for Smash Comics (Quality Comics, 1939 series) #1 (August 1939 and would continue being called Black Ace until #5 (December 1939). With issue #6 (January 1940), he would be called Black X again.