Nathan Fillion's casting as Green Lantern Guy Gardner in Superman: Legacy continues an impressive 7-movie casting record. New DC creative chief James Gunn is in charge of Superman: Legacy, with the executive writing and directing the movie. Superman: Legacy is set to start the new DC Universe in grand style, with the movie beginning to form its cast, which will be anchored by the performances of David Corenswet as Superman and Rachel Brosnahan as Lois Lane. Corenswet will not be playing the only superhero in the movie, as Superman: Legacy is not an origin story, with the film introducing a world where heroes already exist.
https://screenrant.com/nathan-fillion-green-lantern-casting-record-james-gunn/