"The Vatican Tapes" is...just...there. It transcends both 'good' and 'bad', being the reason why the term 'mediocre' exists. I feel like I've seen it before in the form of every other possession movie.
"Deliver us From Evil" doesn't contain a single original idea, other than maybe making Joel McHale into a bad-ass, but it takes those familiar possession concepts and blends them with the clichés of a gritty police drama. This mating of genres is fairy unique and it helps that they have chemistry together, making the film seem more original than it really is.