In the full-length trailer of Captain America Civil War movie, there is a sequence involving Captain America-Bucky The Winter Soldier taking on the Iron Man and there is a mysterious tube in the background where something or someone is preserved or deliberately kept for a particular purpose. So what/who it could possibly be? How is this relevant to the overall plot of the movie?
There is a strong possibility that it’s none other than Quicksilver, who was shot multiple times in the Avengers: Age of Ultron while fighting Ultron and is believed to be dead. But it’s public knowledge that Aaron Taylor-Johnson was signed by Marvel studios for up to three movies, but it’s not the sufficient reason to claim that it’s him considering Hugo Weaving (the Red Skull) had a similar contract with the studio. Anyways after a stipulated time period, contracts of actors expire and maybe it was a contingency plan of Marvel in the first place. Another insane theory is that this may be the clone of Red Skull who went into the cosmic tube and disappeared into nowhere. Adding to that, fans are contemplating that it could be Baron Zemo who might be the clone of Red Skull. This could really tie everything together in the Marvel cinematic universe, particularly for Captain America. There is one important thing that lends credibility to this theory – shooting at the World War- II location.
Last but not the least, the craziest theory is that it’s the clone of Captain America himself, and Red Skull transferred his consciousness to it, so if he dies at the end, this new Captain America can take up the mantle and, by the way, all this has happened in the comic-world.