5. Suicide Squad Is Why We'll Never See Harley Quinn In Arrow
Warner Bros. and DC Entertainment's failure to embrace the concept of a shared universe means that Arrow and The Flash exist in their own world. To avoid conflict with the movies, there are certain characters the shows can't use - Superman and Batman are obvious examples - and others who will disappear from television as soon as the likes of Suicide Squad reach the big screen. Unfortunately, this means no Harley Quinn in Arrow. She was teased in last year's Suicide Squad centric episode, and fans have since been anxiously hoping she might make a return. Rumours pointed to that happening, but it's since been confirmed that the movie means that won't ever happen. As a result, you have to imagine that the Suicide Squad themselves will also vanish from the show. Perhaps The Flash is using the likes of Reverse-Flash and Gorilla Grodd so soon because they know that they will eventually be unable to when the movie hits and ends up using them in 2018?