If theres one big thing in The Force Awakens that demands a prequel film, its the arc of Kylo Ren. He's the son of Leia and Han, trained by Luke before Snoke seduced him to the Dark Side. Years later, he talks to Darth Vader's head and leads a group called the Knights of Ren. Many fans would gobble up a few more details about this story, and although more about Bens turn to evil will surely be revealed in Episode VIII and Episode IX, a spin-off movie could tell us so much more than a dialogue explanation or a flashback. This could be Lucasfilms chance to show George Lucas how a villain-establishing fall-from-grace prequel movie should be done. And, while hes still young enough, if they acted soon they could even get Adam Driver to play the role. Unless they go really far back and show him as a little kid, that is. The trouble this would represent is that Luke, Han and Leia would all need to be in it, and would all need to look significantly younger. Either recasting or using CGI to de-age them could provide a workaround on that one, though. Itd be worth it to see how Kylo came to be, surely.
