Now it's official that Agents of S.H.I.E.L.D. will kickstart Marvel's Civil War, in preparation for next year's Captain America: Civil War. How do I know this? I know this because of the newest episode of Agents of S.H.I.E.L.D.
In the newest episode, we have two different S.H.I.E.L.D. programs, each claiming to be the real S.H.I.E.L.D. One S.H.I.E.L.D. is fighting for the protection of superheroes, and the other for superheroes to be tagged by the government and killed or imprisoned.
The film is expected to present the largest cast of Marvel superheroes to date in the MCU, next to the original Avengers film. It is set to star Chris Evans as Steve Rogers/Captain America, Robert Downey, Jr. as Tony Stark/Iron Man, Chadwick Boseman as T'Challa/Black Panther, Anthony Mackie as Sam Wilson/Falcon, Sebastian Stan as Bucky Barnes/Winter Soldier, Scarlett Johansson as Natasha Romanoff/Black Widow, Frank Grillo as Brock Rumlow, Daniel Brühl as a still-uconfirmed villain.