Among the roles listed are Monica Lynne (King T'Challa's longtime love) and N'Gassi (T'Challa's adviser). The casting call also mentioned the Marvel Comics characters Erik Killmonger and Malice.
Black Panther stars Chadwick Boseman, and the movie opens February 16, 2018.
Movieweb has more below.
Black Panther Villains & Returning Marvel Characters Revealed?