20 Awesome DC TV Easter Eggs You Probably Missed
19. Men Of Steel And Dark Knights (Legends Of Tomorrow)
"I've seen Men of Steel fall and Dark Knights die." Delivered as part of a stirring speech from Rip Hunter, designed to motivate these would-be Legends, but wait, what? Men of Steel? Dark Knights? So, yeah, that's a big nod to Superman and Batman, but while it may just seem like a throwaway line, what it establishes is that the two characters do definitely exist at some stage in The CW's DC universe, even if the likelihood (see: certainty) is that we won't see one of them appear.
Of course, Supergirl itself has introduced Superman, really bringing him into the mix in Season 2. Batman has also been referenced in this world, with the newspaper clipping from the future that Harrison Wells had reporting a merger between Wayne Tech and Queen Incorporated, but it's difficult to see Bats turning up anytime soon.