10 Mistakes Avengers: Infinity War Cannot Afford To Make

3. Thou Shalt Not Introduce Any New Villains

Simple, really: Thanos should take the focus of the movie as its major villain. As outlined in the previous point, he's a monumental character who deserves to be rendered as something more than just a bad guy for a bad guy's sake; audiences need to understand his motives. So given the extent to which the MCU is already packed out with tons of characters, both good and bad, it's important that the movie doesn't try to implement further bad guys for the sake of it - you know, just to make the trailers look good. Age of Ultron learned this lesson the hard way with Andy Serkis' painfully unnecessary Ulysses Klaue. He just wasn't needed. If the movie ends up splitting its time between Thanos and Loki, that's fine; Loki is already positioned as a rich and interesting character - unlike Thanos, he needs no introduction.