It was in 2016 when the Black Panther was introduced to the big screen via the "Captain America: Civil War" film. Since the "Black Panther" movie is set to premiere next year, recent reports claim that the upcoming superhero movie may bring another "Civil War" character in the form of Everett Ross (Martin Freeman).
According to Cinema Blend, Freeman was seen on the set of the "Black Panther" movie. Speculations are loud that the Academy award winning actor might be reprising his role as the tough deputy commander, Everett Ross, whose main task is to hunt Bucky Barnes (Sebastian Stan) when Barnes was framed in killing the king of Wakanda, T'Chaka (John Kani).
The same report also cited that during the 2016 "Captain America: Civil War" film, it was seen that T'challa/ Black Panther (Chadwick Boseman) met Ross in a time of crisis when T'chaka was assassinated during a speech at a world event. The report noted that this might cause issues between the two. However, the publication cited that even if fans might not see T'challa and Ross being friendly to one another at the beginning of the film, it might still be expected that the two will eventually develop a strong alliance, given that Ross is always the ally of T'challa in the comic book version of the "Black Panther."
On the other note, in regards to the other cast members of the "Black Panther" movie, Digital Spy unveiled several actors that fans should expect in the superhero film. It was said that the "Creed" star Michael B Jordan will be joining the crew as Erik Killmonger who is said to be exiled from Wakanda and resents T'Challa.
Another star that joined the cast is Lupita Nyong'o who was seen in "Star Wars: The Force Awakens." Danai Gurira, or Michonne as you call her in "The Walking Dead" series, will play as the Wakandian Dora Milaje. The same publication also cited a familiar character that may be seen on the "Black Panther" movie - the Winter Solider (Sebastian Stan).
As of the moment, there is no official release date for the movie, but speculations are loud that "Black Panther" movie will hit the big screens in February 2018.