Special Guest Stars Grant Gustin as Barry Allen / The Flash Stephen Amell as Oliver Queen / Green Arrow Carlos Valdés as Cisco Ramon / Vibe Caity Lotz as Sara Lance / White Canary Danielle Panabaker as Caitlin Snow / Killer Frost Emily Bett Rickards as Felicity Smoak Stephen Amell as Oliver Queen (Earth-X) / Dark Arrow Tom Cavanagh as Eobard Thawne / Reverse-Flash Tom Cavanagh as Harrison Wells Candice Patton as Iris West Jesse L. Martin as Joe West Dominic Purcell as Mick Rory / Heat Wave Jessica Parker Kennedy as Wedding Caterer Victor Garber as Dr. Martin Stein / Firestorm Keiynan Lonsdale as Wally West / Kid Flash Franz Drameh as Jefferson "Jax" Jackson / Firestorm Guest Stars Danielle Nicolet as DA Cecile Horton Patrick Sabongui as Captain David Singh William Katt as Minister Isabella Hofmann as Clarissa Stein Christina Brucato as Lily Stein Co Starring Mackenzie Gray as Greggor Jeremy Schuetze as Rob Paul Herbert as Scientist Andrea Pizarro as Manicurist Jay MacDougald as Guard Anthony Ames as Angry Boss Robyn Bradley as Wedding Planner Chris Walters as Norman Guard Uncredited Melissa Benoist as Kara Zor-El (Earth-X) / Overgirl Mehcad Brooks as Guardian (Earth-X)
