DC's Legends of Tomorrow - Season 3 - Eps 8: Crisis on Earth-X (IV)
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), Arrow S06E08 Crisis on Earth-X (II) and The Flash S04E08 Crisis on Earth-X (III).
About DC's Legends of Tomorrow

Title: DC's Legends of Tomorrow
First Air Date: 2016-01-21
Last Air Date: 2022-03-02
Status: Canceled
Rating: 7.3/10 (from 2331 votes)
Language: EN
Seasons: 8
Total Episodes: 110
Network: The CW
Genres: Action & Adventure, Sci-Fi & Fantasy, Drama
Production Companies: Warner Bros. Television, Bonanza Productions, Berlanti Productions, DC Entertainment
Synopsis
When heroes alone are not enough ... the world needs legends. Having seen the future, one he will desperately try to prevent from happening, time-traveling rogue Rip Hunter is tasked with assembling a disparate group of both heroes and villains to confront an unstoppable threat — one in which not only is the planet at stake, but all of time itself. Can this ragtag team defeat an immortal threat unlike anything they have ever known?
Cast

Caity Lotz
Sara Lance / White Canary

Tala Ashe
Zari Tarazi

Jes Macallan
Ava Sharpe

Olivia Swann
Astra Logue

Adam Tsekhman
Gary Green

Nick Zano
Nathaniel 'Nate' Heywood / Steel

Shayan Sobhian
Behrad Tarazi

Lisseth Chavez
Esperanza 'Spooner' Cruz

Amy Pemberton
Gideon / Evil Gideon

Matt Ryan
Dr. Gwyn Davies