In addition to Grant Morrison’s The Multiversity, one of the most prominent examples is DC’s Earth-10 universe, which centers on a version of the planet where the Nazis won World War II with the assistance of Nazi Superman called “Overman,” who has already been teased on Supergirl.
Does this animated Overgirl mean we’ll never see a live-action version of either her or Overman?
We can never say never with these shows.
In fact, diving even deeper into the greater DC mythology, there are a few key storylines and characters that appear to have offered up some pretty clear inspiration for Freedom Fighters: The Ray.