For those who’re keeping score, the original DC Comics version of Mister Sinister made his debut way back in Superman #16 (May 1942) by Jerry Siegel, Wayne Boring, Leo Nowak, Fred Ray, and John Sikela.
Sounds a lot like the regular Marvel Universe version, doesn’t he?
This appearance of the original DC Comics version of Dr. Doome has been brought to you by Leading Comics #3 (June 1942) by Henry Boltinoff, Cliff, Perry Davis, Jack Lehti, Mort Meskin (a.k.a. Mort Morton), and Hal Sherman.