Black Adam has completed shooting, so hopefully we will start seeing some promotional material for it, at least as far as to how all the characters will look in the film. I have a feeling that there may be some special effects that go into bringing Doctor Fate to life, so it may still be a while before we see how he will be visualized.
This rivalry started a while ago. The imprisonment that Ghost Rider speaks of here took place way back in STF #233. Dr. Fate didn't get along much better with Danny Ketch in STF #2391...