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
For several years, Nightwing leads various incarnations of the Titans and becomes the most respected former sidekick in the DC Universe. However, in the "" crossover, a rogue Superman android kills Lilith and Troia, an event that tears apart both Young Justice and the Titans. At Troia's funeral, Dick declares he is tired of seeing friends die and disbands the team, officially ending the Titans. A few months later, Arsenal persuades Nightwing to join a new pro-active crime-fighting team: the Outsiders, who would hunt villains, acting as co-workers rather than an extended family. He reluctantly accepts.