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 David Ramsey as John Diggle Danielle Panabaker as Caitlin Snow Carlos Valdés as Cisco Ramon Wentworth Miller as Leonard "Leo" Snart / Citizen Cold Chyler Leigh as Alex Danvers Juliana Harkavy as Dinah Drake / Black Canary Rick Gonzalez as Rene Ramirez / Wild Dog Echo Kellum as Curtis Holt / Mr. Terrific Melissa Benoist as Kara Zor-El (Earth-X) / Overgirl Stephen Amell as Oliver Queen (Earth-X) / Dark Arrow Tom Cavanagh as Eobard Thawne / Harrison Wells / Reverse-Flash Tom Cavanagh as Harrison Wells 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
