She played Claire Temple in Daredevil and is set to appear in Jessica Jones. It makes sense that Claire would reappear in Luke Cage as the two had a close relationship in the comics.
Also joining the series is Theo Rossi (Sons of Anarchy) as the villain Shades (a.k.a. Alvarez). Little is know about this interpretation of the character at this point, but he’s described as being “relentless and menacing, smooth and manipulative, street smart and controlling.”
Arguably the biggest addition to Luke Cage’s corner of Hell’s Kitchen is relative unknown Simone Missick as Misty Knight. In the comics, she’s a cop who’s injured in the line of duty and ends up getting a bionic arm courtesy of Tony Stark. Misty eventually ends up dating Iron Fist, another character set to receive his own series in the near future.
It’s not clear what stage of her career Misty will be at when we meet her in Luke Cage as she’s only described by Marvel at this stage as, ” a woman with a strong sense of justice.”