Origin

Exposed to "the sizzling voltage of a secret current" Brad Spencer finds that he can make himself as hard a steel and super strong, so calling himself Wonder Man he battles crime and/or evil, and eventually starts to take on monsters from space while engaged in adventures in space.

After a time he finds how to recreate what gave him his powers and his girlfriend Carol Paige becomes Wonder Girl, he also creates an artificial man whom he calls Roboroy.

Character Evolution

Appearing in a few Better / Standard / Nedor comics in the 40's he and other Nedor characters such as the Black Terror, Tom (Doc) Strange, & the Grim Reaper reappear in slightly different form in the pages of Alan Moore's Tom Strong.

While they both appeared in Wonder Comics, here is no connection between this Wonder Man and Grim Reaper and characters with the same names at Marvel.