Victor Garber Professor Stein, Half of Firestorm Actor Brandon Routh Ray Palmer, Atom Actor Dominic Purcell Mick Rory, Heat Wave Actor Nick Zano Dr. Nate Heywood, Citizen Steel Actor Caity Lotz Sara Lance, White Canary Actor Franz Drameh Jefferson "Jax" Jackson, Half of Firestorm Actor Maisie Richardson-Sellers Amaya Jiwe, Vixen Actor Amy Louise Pemberton Gideon Voice Tala Ashe Zari Adrianna Tomaz Actor Neal McDonough Damien Darhk Actor Keiynan Lonsdale Wally West, Kid Flash Actor Stephen Amell Oliver Queen, Green Arrow Guest Star David Ramsey John Diggle Guest Star Emily Bett Rickards Felicity Smoak Guest Star Tom Cavanagh Dr. Harry Wells, Eobard Thawne, Reverse-Flash Guest Star Chyler Leigh Alex Danvers Guest Star Candice Patton Iris West Guest Star Danielle Panabaker Caitlin Snow, Killer Frost Guest Star Carlos Valdes Cisco Ramon, Vibe Guest Star Echo Kellum Curtis Holt, Mr. Terrific Guest Star Rick Gonzalez Rene Ramirez, Wild Dog Guest Star Juliana Harkavy Dinah Drake, Black Canary Guest Star Melissa Benoist Kara Danvers, Supergirl, Overgirl Guest Star Grant Gustin Barry Allen, The Flash Guest Star Wentworth Miller Leo Snart, Citizen Cold Guest Star Russell Tovey Ray Terrill, The Ray Guest Star Christina Brucato Lily Stein Guest Star Isabella Hofmann Clarissa Stein Guest Star Greg Berlanti Executive Producer Marc Guggenheim Executive Producer Andrew Kreisberg Executive Producer Phil Klemmer Executive Producer Chris Fedak Executive Producer Sarah Schechter Executive Producer