Special Guest Stars Stephen Amell as Oliver Queen / Green Arrow Melissa Benoist as Kara Danvers / Supergirl Katherine McNamara as Mia Smoak Tom Welling as Clark Kent of Earth-167 Tyler Hoechlin as Clark Kent / Superman Grant Gustin as Barry Allen / The Flash Matt Ryan as John Constantine Brandon Routh as Ray Palmer / The Atom Brandon Routh as Clark Kent / Superman of Earth-96 Caity Lotz as Sara Lance / White Canary Elizabeth Tulloch as Lois Lane Elizabeth Tulloch as Lois Lane (Earth-75) Dominic Purcell as Mick Rory / Heat Wave of Earth-74 Candice Patton as Iris West-Allen Jon Cryer as Lex Luthor Guest Stars Wentworth Miller voices Leonard A.I. Erica Durance as Lois Lane of Earth-167 Audrey Marie Anderson as Lyla Michaels / Harbinger Kevin Conroy as Bruce Wayne / Batman of Earth-99 Johnathon Schaech as Jonah Hex of Earth-18 Co Starring Elias Hogewoning as Baby Jonathan Kent Benjamin Hogewoning as Baby Jonathan Kent
