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.
Dick Grayson
The "Nightwing" title concluded in April 2014 at issue #30, and was replaced with a new title, "Grayson", which depicts Dick having given up his life as Nightwing at age 22 and going undercover as an agent of the Spyral organization where the former Batwoman Kathy Kane works. Written by Tim Seeley and former CIA counter-terrorism officer Tom King, the career change for Dick Grayson comes from the urging of Batman himself, who convinces him to remain dead to the world. Seeley stated that the series will be "leaning into" Grayson's sex symbol status. The character's look also is redesigned with no mask, but a blue-and-black outfit calling back to his pre-New 52 Nightwing counterpart with an addition of a "G" on his chest, said to be reminiscent of the Robin "R".