Flash Gordon (film)/WMG

The 2007 series's Ming is Flash's father
First, Ming was revealed to be Caucasian rather than an Asian type.

Then there was a throwaway reference to time dilation between Earth and Mongo - enough for Ming's daughter to have been born after Mr. Gordon was trapped there.

Then there was The Reveal that Ming was chasing the youth vampire because she had been keeping him young. A Fountain of Youth is necessary for this theory, since Ming is {physically} younger than Mr. Gordon. It so happens that there is one.

The twist at the end of the 'trapped on Mongo' two-parter -- that the prisoner was lying about Mr. Gordon being executed -- makes this theory more likely.

Mongo in the 1980 movie became the world of The Big O
After Flash saved Mongo and Earth, the Mongans were ruled over by Prince Barrin peaceably. But Prince Barrin abandoned Mongo to become a certain secret agent. Then Mongo descended into chaos. The Mongans became darker and more mundane until their entire way of life became dreary. All that remained was the hope of a great hero to save them and Flash Gordon's theme music - which the theme music of The Big O sounds suspiciously like.