I'm thinking the Shyamalan twist is that Josh Hartnett's character is a Dexter-like Serial Killer that enjoys killing Serial Killers and that the movie won't focus on "The Butcher" but rather him beijg trapped in this Stadium with several other Serial Killers that will eventually sus each other out and their collective paranoia wilk cause the events of the film to escalate into pure chaos.

Appreciate the honesty. Yeah, you can tell sometimes that a person has seen the content already. Actual first time reactions are better.