9. Cyclops
I know what you're thinking; wait a minute - isn't Cyclops dead? Whenever a character dies off-screen, there's every chance they're still alive, plus, this is comics - anything can happen. Though it seemed like Jean Grey spirited away Cyclops mid-way through The Last Stand, it would be a piece of cake to bring him back, something even Brett Ratner seemed to entertain the idea of by not giving him a definitive demise in the film itself. And how could this tie perfectly into Days of Future Past? It might be a
little bit of a leap, but what if Jean Grey was somehow able to send Cyclops through time with her Phoenix powers, and he has now wound up in the early 1970s, when Days of Future Past is initially set before the time travel headache begins? It would certainly allow for some intriguing dialogues between Cyclops and the young'uns, alongside grand humour and also some potentially Earth-shattering implications for the, ahem, future of the franchise.