On Thursday, September 20, David Gordon Green’s Halloween kicked off Fantastic Fest 2018. While that was a very fitting way to start one of the world’s largest genre film festivals, it wasn’t the first feature I saw this year (thank you press screening room!). And, truth be told, You Might Be the Killer is actually a film better suited to usher in the 14th year of this glorious festival. It’s more representative of what a genre film is, and one that has been lovingly constructed by cherry-picking elements of seminal slashers to offer something funny, fresh, reverent and thoroughly enjoyable. And it’s all based on this brilliant Twitter exchange between Sam Sykes and Chuck Wendig.…