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
During one of his nightly patrols with Batman, Nightwing is shot by KGBeast and nearly killed. As a result, he suffered from severe memory loss and attempted to build a new life in Bludhaven. He changed his name to Ric, gave up being Nightwing, and became a taxi driver that frequently went to bars. With Bludhaven suffering from an increase in crime from the vigilante's absence, a detective named Sapienza comes across Dick's abandoned hideout in the subway and decides to become the new Nightwing.