Originally Posted by
Osiris-Rex
Nothing to stop them from using Metallo again. There have been five Metallos already. The original John Corben plus the lab tech in season 2 of Supergirl, an un-named Metallo in Crisis on Earth-X, another
unamed Metallo and Otis Graves in season 4 of Supergirl.
Just because there was a Bizarro Supergirl doesn't mean there can't be a Bizarro Superman.
There have been two Parasites, Rudy Jones and the DEO agent that was recruited by Mercy Graves. So no limit on Parasites.
Apparently Zod comes back to life sometime in the future so why not sooner than later?
Toyman had a female protege making evil toys so why not have another disciple of Toyman.
Mxyzptlk was merely sent back to the 5th dimension. So either bring the original actor back or explain he can change his appearance.
There seems to be more than one Black Mercy so they could do the Superman version of For the Man Who Has Everything. It will have been 6 years since Supergirl
did the story so it shouldn't feel too much of a rehash, been there done that.
So really no reason Superman can't recycle villains used on Supergirl. They may not be the original, such as in the case of John Corben or Rudy Jones. But does it really matter if someone
else is the villain as long as they have the same powers.