Wow. What a clever film. The title seems like a spolier, right? It actually means John will die at the end of the world, which he keeps preventing, so he never actually dies! Clever, like I said.
How to describe the genius of the plot? It starts as a zombie film, then becomes a highschool geek’s fantasy of his life, which turns out to be true but actually a bad drug trip, but the drug is sentient and enables him to see the dead (explaining the film’s beginning) and the demons that are trying to enter our world in order to destroy it. And the supreme demon needs to be confronted in his own realm if we are to be saved! Clever, clever. The frame of reference and genre of the film constantly changes, meaning we are never ever cleverly bored. It keeps us on our toes, constantly surprised and constantly entertained. And there’s a good dose of irony and humour.
Go watch it, honestly. It has decent production values and Paul Giamatti has a decent role in it. It scores a triumphant 9/10 from me!