Deadline reports Rossi will be a series regular opposite Mike Colter as Luke Cage with the role said to be relentless and menacing, smooth and manipulative, street smart and controlling. It's said Rossi will be playing Luke Cage’s enemy Shades aka Alvarez, a well known criminal.
It's further reported Rosario Dawson will reprise her Claire Temple role in Luke Cage as well. As noted, Temple is a love interest to Cage in the comics, and Dawson is slated to appear in Jessica Jones prior to Luke Cage.
It was reported a while back that Alfre Woodward will be playing the Marvel Comics villain Black Mariah.
Update: It's also reported Simone Missick has been cast as Misty Knight described as a woman having a strong sense of justice. In the comics, Mistky Knight is a former NYPD officer who gets a new bionic arm by Tony Stark after losing hers in the line of duty. She eventually launches a detective agency, helping Cage.