Nightwing
Although Nightwing is commonly associated with Batman, the title and concept have origins in classic Superman stories. The original Nightwing in DC Comics was an identity assumed by alien superhero Superman when stranded on the Kryptonian city of Kandor with his pal Jimmy Olsen. Drawing inspiration from Batman and Robin, the two protect Kandor as the superheroes Nightwing and Flamebird. Following the Crisis on Infinite Earths continuity reboot in 1985, Nightwing was re-imagined as a legendary vigilante from Krypton whose story inspires Dick Grayson's choice of name when he leaves behind his Robin identity.
Nightwing
Following the erasure of the knowledge regarding his secret identity from most of the world in the final issue of "Grayson", Dick went back to the Nightwing identity in the DC Rebirth era solo series, and the costume's colors were changed back to the traditional black and blue. At the start of the series (rebirth) Nightwing is still a member of the Court of Owls (after Robin War) and he goes on missions around the world for the Court. They give him a partner named "Raptor" and like Nightwing he wears a costume, but he is much more violent than Dick and multiple times Dick has to try to stop him from killing. Throughout the story arc, Dick must work as an undercover agent but also has to keep his morals and not kill even if the Court tells him to.