Use of Luthor
Funny how DC would not let Columbia use any of the BATMAN bad guys and yet here we have Luthor in the 2nd SUPERMAN serial odd
See some stars here
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Maybe DC wanted to obliterate the radio show 'Atom Man' story, which is completely different, and overlay a story with a connection to the comix. (The radio Atom Man story is better than this.)
Another thing: The 'empty doom' here was adopted by the comix and retitled 'The Phantom Zone.'
The licensing for these serials is odd business. DC wanted (and got) more control of their characters than Marvel or Fawcett did (see the Republic Captain America and Capt. Marvel serials). Maybe DC wanted Columbia to pimp Luthor.
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