Superman: Legacy's Green Lantern casting divides DC Universe fans on social media. James Gunn's first movie in Chapter 1 of the DCU, "Gods and Monsters," has ramped up its star-studded cast, with frequent Gunn collaborator Nathan Fillion joining the project as Guy Gardner, aka Green Lantern. Fillion has appeared in some capacity in every Gunn project. Most recently, this was in Guardians of the Galaxy Vol. 3, and he also played T.D.K. in Gunn's The Suicide Squad, which was a part of the now-defunct DCEU.
https://screenrant.com/superman-legacy-green-lantern-nathan-fillion-reactions/