T’Challa/Black Panther
T’Challa/Black Panther (Chadwick Boseman) is new to the MCU, and Captain America: Civil War is his introduction to audiences. This means that, in terms of the way in which the character will be established in the film franchise, we have no real idea of his motivations, nor where his allegiances will ultimately lie.
We know, from the comic book source material, that the primary motivation for the character is the murder of his royal father, at the hands of Ulysses Klaue, in his home nation of Wakanda.
In the trailer for Captain America: Civil War, however, he is glimpsed being caught up in the collateral damage caused by one of the previous superhero incidents. This fits well with trailer shots of Black Panther, in full costume, fighting alongside Iron Man, who is a supporter of government oversight. Judging by the preview footage, Black Panther will be a powerful ally to have.
[zergpaid]Wanda Maximoff/Scarlet Witch
Wanda Maximoff/Scarlet Witch (Elizabeth Olsen) lost her brother, Pietro Maximoff/Quicksilver, in Avengers: Age Of Ultron – and this was her primary motivation to work with the Avengers. Though she was hostile toward them at first, she finds herself fighting alongside them to defeat Ultron, and reluctantly joining their ranks, since she has no other family left and nowhere to go.
For Scarlet Witch – who first appeared in the custody of Hydra, regarded as a potential weapon – joining the Avengers is, in itself, an act of submitting to authority. She had hitherto only herself and her brother to answer to, since Hydra kept them both incarcerated. When her brother dies, she must choose between isolation, or joining a team and accepting all the implications that go along with it. Opting for teamwork, Scarlet Witch is faced with a new level of accountability – although to her colleagues who have a different life experience, this may equate to very little accountability at all.
For these reasons, it comes as little surprise that Scarlet Witch appears in the trailer of Captain America: Civil War alongside Captain America, as he prepares to battle Iron Man and fend off governmental interference in his activities. She can relate to the idea of operating upon one’s own initiative, and she can relate to both Captain America and Bucky Barnes – who are people that have found themselves outside of their original circumstance, struggling to fit in.