My idea for the movie is to do it as a horror movie version of Dirty Rotten Scoundrels.
As long as there have been horror movies, there have been attempts to mix together horror movie characters in crossover films.
Why, just recently, who can forget Freddy vs. Jason, the critically reviled — but financially successful — 2003 film that pitted the stars of the Friday the 13th and Nightmare on Elm Street franchises against each other?
If Mancini is really serious about getting this made, maybe it would work best as an animated movie?