Special Guest Stars Victor Garber as Dr. Martin Stein / Firestorm Stephen Amell as Oliver Queen / Arrow Emily Bett Rickards as Felicity Smoak Melissa Benoist as Supergirl / Kara Zor-El / Kara Danvers Chyler Leigh as Alex Danvers Caity Lotz as Sara Lance / White Canary Franz Drameh as Jefferson "Jax" Jackson / Firestorm Wentworth Miller as Leonard "Leo" Snart / Citizen Cold Melissa Benoist as Kara Zor-El (Earth-X) / Overgirl Emily Bett Rickards as Felicity Smoak (Earth-X) Stephen Amell as Oliver Queen (Earth-X) / Dark Arrow Paul Blackthorne as Sturmbannfuehrer Quentin Lance Juliana Harkavy as Dinah Lance / Black Canary Jeremy Jordan as Freedom Fighter General Schott Guest Stars Russell Tovey as Raymond Terrill / The Ray Co Starring Micah Steinke as Nazi Soldier #1 Brett Alexander Davidson as Nazi Facility Guard Brian Cook as Nazi Frederick Schmidt voices Metallo-X
