Superman Smashes the Klan was adapted from a mid-1946 arc in the Superman radio series, and the Atom Man in Yang's comic was based on the original Atom Man who appeared on radio in late 1945. Atom Man was the one real superpowered villain Superman faced on radio, a sort of proto-Metallo -- a Nazi agent with kryptonite in his blood and special gauntlets that could focus it into deadly atomic rays, making him potentially as destructive as an atom bomb. His battle with Superman was the series's most epic storyline, running 38 episodes within a longer 76-episode kryptonite arc. The 1950 serial took the name Atom Man and combined it with the totally unrelated Luthor character from the comics.