Special Guest Stars Stephen Amell as Oliver Queen / Green Arrow Grant Gustin as Barry Allen / The Flash Emily Bett Rickards as Felicity Smoak Melissa Benoist as Supergirl / Kara Zor-El / Kara Danvers Danielle Panabaker as Caitlin Snow Wentworth Miller as Leonard "Leo" Snart / Citizen Cold David Ramsey as John Diggle / Spartan Carlos Valdés as Cisco Ramon Chyler Leigh as Alex Danvers Echo Kellum as Curtis Holt / Mr. Terrific Rick Gonzalez as Rene Ramirez / Wild Dog Juliana Harkavy as Dinah Drake / Black Canary Tom Cavanagh as Eobard Thawne / Harrison Wells / Reverse-Flash Tom Cavanagh as Harrison Wells Stephen Amell as Oliver Queen (Earth-X) / Dark Arrow Melissa Benoist as Kara Zor-El (Earth-X) / Overgirl Candice Patton as Iris Ann West Guest Stars Christina Brucato as Lily Stein Isabella Hofmann as Clarissa Stein Russell Tovey as Raymond Terrill / The Ray Co Starring Charles Zuckermann as Nazi Commander Adam Klassen as Nazi Navigator Uncredited Susanna Thompson as Gideon-X
