Most are saying that Mark Hamill's return to the role that made him famous besides The Joker, anyway despite him not doing a lot will involve him...still not doing a lot. In fact the most popular theory is that the older, wiser Luke Skywalker will provide a similar role Alec Guinness's Ben Kenobi did in the first film, passing on his knowledge (and possibly his lightsabre) onto a protege. But what if they try something completely different? Thirty years is a long time. What if, without the guidance of either Ben or Yoda, Luke goes a little off the rails? There's a precedent for it in the Skywalker family, what with all that nasty Anakin/Darth Vader business. Perhaps things didn't work out so well for him after the fall of the Empire. Maybe the allure of power was just too much. On-screen photographs suggest that Luke spends some time locked up in a sort of interplanetary jail. Some speculated he was put in there by the bad guys, but what if he was put in there because he was a bad guy and Daisy Ridely breaking him out is either hugely misguided, or a bad 'un herself? Twisting the Original Trilogy's purest character into pure evil would be pretty ballsy. And cool.