Arrow - Season 6 - Eps 8: Crisis on Earth-X (II)
Barry and Iris’s wedding brings the gang together, but things go awry when villains from Earth-X attack the ceremony. All of the superheroes band together with help from their super friends like Citizen Cold, The Ray, Felicity Smoak, Iris West and Alex Danvers to take on their most formidable villains yet. Earth’s mightiest heroes – Green Arrow, Supergirl, The Flash and White Canary – lead their teams into battle to save the world. The crossover starts on Supergirl S03E08 Crisis on Earth X (I). It continues on The Flash S04E08 Crisis on Earth-X (III) and DC's Legends of Tomorrow S03E08 Crisis on Earth X (IV).
About Arrow

Title: Arrow
First Air Date: 2012-10-10
Last Air Date: 2020-01-28
Status: Ended
Rating: 6.822/10 (from 6048 votes)
Language: EN
Seasons: 9
Total Episodes: 170
Network: The CW
Genres: Crime, Drama, Action & Adventure
Production Companies: Berlanti Productions, DC Entertainment, Warner Bros. Television
Synopsis
Spoiled billionaire playboy Oliver Queen is missing and presumed dead when his yacht is lost at sea. He returns five years later a changed man, determined to clean up the city as a hooded vigilante armed with a bow.
Cast

Stephen Amell
Oliver Queen / Green Arrow

Rick Gonzalez
Rene Ramirez / Wild Dog

Katherine McNamara
Mia Smoak / Blackstar

David Ramsey
John Diggle / Spartan

Katie Cassidy
Laurel Lance / Black Canary

Juliana Harkavy
Dinah Drake / Black Canary

Joseph David-Jones
Connor Hawke

Ben Lewis
Adult William Clayton