X-Men: Days of Future Past director Bryan Singer told the Spanish language Website that he wants to bring back two mutants, Nightcrawler and Gambit, for his next X-Men film, X-Men: Age of the Apocalypse.  Nightcrawler, who was interpreted brilliantly by Alan Cummings, was one of the key characters in Singer’s X2, and Gambit, who was played by Taylor Kitsch, had a big role in X-Men Origins: Wolverine, but these particular mutants have been MIA in recent X-Films.
 
Singer has an obvious affection for the character of Nightcrawler. He told Cine-Premiere: "I was going to have Nightcrawler in Days of Future Past, and even wrote a scene, but I felt that we were forcing too many mutants into known history."  There has been some discussion of a Gambit movie, and perhaps it could even be the unnamed Marvel-based movie that Fox has reserved a date for in 2018 (see "Fox Claims Dates for 'FF' & 'Wolverine' Sequels"), though there are other more likely candidates.