After rolling a new Season 3 trailer out at the top of the Warner Bros. panel, “Legends of Tomorrow” executive producers Marc Guggenheim and Phil Klemmer took the Comic-Con stage with cast members Tala Ashe, Dominic Purcell, Nick Zano, Caity Lotz, Brandon Routh, Maisie Richardson-Sellers, Victor Garber, and Franz Drameh.