In a run-down Las Vegas wax museum, a washed-up musician enlists the help of Elvis Presley to save Sin City from one of history’s worst villains.

Excellent.  That sums it up well.  Thanks.

My idea of the villain is just a single character from history  who feels slighted that he was ignored by history .   Perhaps Tesla who was into some pretty interesting work.   Edison got all the headlines.  All Tesla got was a car named after him.

Or a contemporary of Houdini who was a spiritualist that Houdini made fun of  in his acts.