Not everyone lives forever. Not even superheroes. And even if they do live long enough to suggest otherwise, they usually hang up the cape and tights before they get too over the hill. And sooner or later especially when it comes to those heroes that have inherited or inspired a legacy theyre going to need to pass the torch on to someone else. This is a problem no more keenly felt that in superhero movies, where actors are lucky if they get to play a costumed crime-fighter in one movie, let alone half a dozen, and Batman actors are recast roughly twice a decade. Marvel, however, have developed a stunning formula over the past six years in which the same actors (Terrence Howard and Ed Norton notwithstanding) have managed to portray the same characters in a series of interconnected movies. Its a hugely impressive juggling act, but the studio is nearing the point where theyll have to make some serious decisions about how they move their franchises forwards when their best-known performers and/or their characters are no longer in the picture. Its been hinted that both Robert Downey, Jr. and Chris Evans may be making their MCU swansongs soon, and with the internet abuzz with all kinds of rumours about whether Marvel will replace the characters with others from the comics/movies or simply recast, it seems about the right time to talk about who else could replace some of the MCUs biggest hitters when theyre not around anymore in addition to characters in movies that arent quite in the same universe but were still originated by Marvel. Read on for our picks of the ten best second-generation heroes we might just see in the future.