It won't happen but what if one studio was able to buy up all the rights to the big slashers and put them all into the same universe? If there was an "Avengers" style mashup movie where a whole bunch of slashers appeared in the same film? what do you think the plot would be?
I can imagine something like someone solves the Lament configuration to summon Pinhead and summons the Djinn from Wishmaster at the same time. Both Pinhead and the Djinn are either immortal or nigh immortal, so fighting each other over the soul of that person wouldn't work. Thus, they make a game to bring together the most evil people in the world to fight on their behalf, and whichever side wins gets to claim that person's soul.
So all the big and some of the small hitters would be there, Leatherface, Michael Myers, Jason Voorhees, Freddy Kreuger, Pumpkinhead, Chucky, Leprechaun, Candyman, The Tall Man, the Children of the Corn(with He Who Walks Behind the Rows as like a "special summon" ability like in CoTC 3 lol)and so on for anyone else I forget.
So what do you think would happen based on something like that opening act?