Rise of the Guardians: Crisis on Earth X

Rise of the Guardians: Crisis on Earth-X is the name of the fourth annual Guardian Arrowverse crossover event. Due to the event going over four separate series, it's condensed into an eleven-act film.

Summary
Everyone comes together to celebrate Cisco and Lorelai's wedding, but when Nazis crash the ceremony, everything's turned upside down. The Guardian's destiny is upon them as Elizabeth's life is at risk, at the claws of her eldest sister Chey-Gon/Lilith. It's a race against a ticking clock. Can the Guardians save their princess? Or will their Earth fall under the tyranny of the Dark Dragon Queen?.

Cast
(due to multiple characters from all Arrowverse shows appearing in this crossover, cast will be listed by the order which they appear. Some actors will be listed more than once due to them portraying multiple roles.)


 * Mehcad Brooks as James Olson's Earth-X doppelgänger: A member of the Freedom Fighters who's killed in the prologue by the Dark Guardians and Dark Arrow.
 * Dianna Agron as Claire Daniels/Jewel: Claire's Earth-X doppelgänger and member of the Dark Guardians; five women bonded to the Dark Animal Gems created by Chey-Gon in order to solidify her power over Earth-X. Jewel's powers include Psychokinesis, Telepathy and Mind Control. During the invasion of Earth-1, Jewel fights her doppelgänger Carbuncle and is killed by Lilith, who then absorbs her powers.
 * Vanessa Morgan as Selena Merlyn/Black Wolf: Selena's Earth-X doppelgänger and the leader of the Dark Guardians, five women bonded to the Dark Animal Gems created by Chey-Gon in order to solidify her power over Earth-X. Black Wolf's powers include Shadow Teleportation and Shadow Manipulation, and partial animal transformation (fangs, claws, and glowing eyes). She is also the younger sister of Tommy Merlyn/Prometheus. During the invasion of Earth-1, Black Wolf fights her doppelgänger Lunar Wolf and is killed by Lilith, who then absorbs her powers.
 * Nina Dobrev as Andrea Rayne/Shadow Fox: Andrea's Earth-X doppelgänger and second-in-command of the Dark Guardians, five women bonded to the Dark Animal Gems created by Chey-Gon in order to solidify her power over Earth-X. Shadow Fox's powers include Stealth, Heightened Senses, and the ability to perceive what isn't all there. She is also the occasional lover of Oliver/Dark Arrow. During the invasion of Earth-1, Shadow Fox fights her doppelgänger Arctic Fox and is killed by Lilith, who then absorbs her powers.
 * Troian Bellisario as Lorelai Snart/Black Grizzly: Lorelai's Earth-X doppelgänger and member of the Dark Guardians; five women bonded to the Dark Animal Gems created by Chey-Gon in order to solidify her power over Earth-X. Black Grizzly's powers include increased Strength and Durability, and control over water in all its forms (solid, liquid, and gas). She is also the younger sister of Leo Snart/Citizen Cold and the late Lisa Snart, and was the object of the late Vibe's affections before being forcibly bonded to the Dark Bear's Head. During the invasion of Earth-1, Black Grizzly fights her doppelgänger Ice Princess and is killed by Lilith, who then absorbs her powers.
 * Cassie Scerbo as Elena Queen/Blood Raven: Elena's Earth-X doppelgänger and member of the Dark Guardians; five women bonded to the Dark Animal Gems created by Chey-Gon in order to solidify her power over Earth-X. Blood Raven's powers include Atmokinesis and its sub-forms (Aerokinesis, Electrokinesis, and Nephelokinesis), and the ability to manipulate soundwaves via her vocal cords. She is also the younger sister of Dark Arrow and was the object of Red Arrow's affections before being forcibly bonded to the Dark Eagle's Head. During the invasion of Earth-1, Blood Raven fights her doppelgänger Thunder Eagle and is killed by Lilith, who then absorbs her powers.
 * Stephen Amell as Oliver Queen/Dark Arrow: Oliver's Earth-X doppelgänger, also known as "Führer", the leader of the New Reich on Earth-X and one of the four generals serving under Chey-Gon alongside the Dark Guardians. He is the best friend of Tommy Merlyn/Prometheus, the older brother of Dark Guardian Elena/Blood Raven, and the occasional lover of Dark Guardian Andrea/Shadow Fox. During the invasion of Earth-1, Dark Arrow fights his doppelgänger Green Arrow and is killed by him during battle.
 * Holland Roden as Chey-Gon/Lilith: The eldest daughter of Qui-Gon, the eldest sister of Sol-Gon/Emily Sparks and Sei-Gon/Elizabeth Mendel and the "Drachenkönigin" ("Dragon Queen") of Earth-X. She commands the Dark Guardians and the New Reich. When it's discovered she's dying due to radiation poisoning, she seeks out her youngest sister, Elizabeth, and intends to steal her heart and powers in order to cure herself and continue her rule over the rest of the multiverse. During the invasion of Earth-1, Lilith fights Elizabeth, and in trying to defeat her, kills her Dark Guardians and absorbs their powers, which overloads her and causes her death.
 * Grant Gustin as Barry Allen/The Flash: A hero of Earth-1's Central City and leader of Team Flash. He's the boyfriend of Claire Daniels/Carbuncle, best friend of Iris West-Daniels and Cisco Ramon/Vibe, foster son of Joe West and foster brother of Wally West/Kid Flash. During the wedding ceremony, Barry stands up as Cisco's best man. During the invasion of Earth-1, Barry faces off against his nemesis Eobard Thawne/Reverse Flash.
 * Dianna Agron as Claire Daniels/Carbuncle: A hero of Earth-1's Central City and member of Team Flash. She's the girlfriend of Barry Allen/The Flash, the younger sister of Theo Daniels, best friend and sister-in-law of Iris West-Daniels. Claire is also a member of the Guardians, wielding the power of the Carbuncle gem. Her powers include Advanced Psychokinesis, Telepathy, advanced Empathy, and the ability to heal others. During the invasion of Earth-1. Claire fights her doppelgänger Jewel and watches as Lilith kills her. During the wedding ceremony, Claire is one of Lorelai's bridesmaids.
 * Holland Roden as Sei-Gon/Elizabeth Mendel/Mother Nature: A Drakonian, hero of Earth-1's Central City and member of Team Flash. She's the mother of twins, Josh and Jasmine, and the love interest of Harry Wells. Elizabeth is also the youngest daughter of Qui-Gon, and the youngest sister of Chey-Gon/Lilith and Sol-Gon/Emily Sparks. She's also known as the "Dragon Princess" that the Guardians are meant to protect, and her powers include various forms of Elemental Manipulation. During the invasion of Earth-1, Elizabeth fights Lilith and gains the upperhand, with the help of her five Guardians. During the wedding ceremony, Elizabeth is one of Lorelai's bridesmaids.
 * Candice Patton as Iris West-Daniels: A civilian member of Earth-1's Team Flash. She's the daughter of Joe West, older sister of Wally West/Kid Flash, the wife of Theo Daniels, best friend of Barry Allen/The Flash and sister-in-law of Claire Daniels/Carbuncle.
 * Paul Wesley as Theo Daniels: A civilian member of Earth-1's Team Flash and Assistant District Attorney. He's the older brother of Claire Daniels/Carbuncle, husband of Iris West-Daniels, brother-in-law of Wally West/Kid Flash, and son-in-law of Joe West. During the wedding Ceremony, Theo stands up as one of Cisco's groomsmen.
 * Cassie Scerbo as Elena Queen/Thunder Eagle: A hero of Earth-1's Star City and member of Team Arrow. She's the younger sister of Oliver Queen/Green Arrow and best friend of Lorelai Snart/Ice Princess. Elena is also a member of the Guardians, wielding the power of the Eagle's Head gem. Her powers include Atmokinesis and its sub-forms (Aerokinesis, Electrokinesis, and Nephelokinesis), and the ability to manipulate soundwaves via her vocal cords. During the invasion of Earth-1. Elena fights her doppelgänger Blood Raven and watches as Lilith kills her. During the wedding ceremony, Elena is Lorelai's Maid of Honor.
 * Carlos Valdes as Cisco Ramon/Vibe: A hero of Earth-1's Central City and a member of Team Flash. He's the fiancée of Lorelai Snart/Ice Princess and best friend of Barry Allen/The Flash. During the invasion of Earth-1, Cisco stays on the Waverider with Harry and breaches the trio of Killer Frost, Vixen, and Zari back before the Wellenrieter is destroyed. At the end of the crossover, Cisco marries Lorelai, the ceremony being officiated by their friend, John Diggle, and the two head to Coast City to begin their honeymoon.
 * Troian Bellisario as Lorelai Snart/Ice Princess: A hero of Earth-1's Central City and a member of Team Flash. She's the youngest sister of the late Leonard Snart/Captain Cold and Lisa Snart/Golden Glider, the fiancé of Cisco Ramon/Vibe, and best friend of Elena Queen/Thunder Eagle. Lorelai is also a member of the Guardians, wielding the power of the Bear's Head gem. Her powers include increased strength and durability, Ice Manipulation, advanced manipulation of water in all its forms (solid, liquid, and gas). During the invasion of Earth-1, Lorelai fights her doppelgänger Black Grizzly and watches as Lilith kills her. At the end of the crossover, Lorelai marries Cisco, the ceremony being officiated by their friend, John Diggle, and the two head to Coast City to begin their honeymoon.
 * Dove Cameron as Rachel Rayne-Merlyn/Oracle: A civilian member of Earth-1's Team Arrow. She's the younger sister of Andrea Rayne/Arctic Fox and the wife of Selena Merlyn-Rayne/Lunar Wolf, and adoptive mother of Damien Merlyn-Rayne. For most of the crossover, Rachel stays behind in S.T.A.R. Labs along with Iris and Theo, and later helps the heroes by disabling the Wellenreiter's shields.
 * Vanessa Morgan as Selena Merlyn-Rayne/Lunar Wolf: A hero of Earth-1's Star City and second-in-command of Team Arrow. She's the wife of Rachel Rayne-Merlyn/Oracle and adoptive mother of Damien Merlyn-Rayne. Selena is also the leader of the Guardians, wielding the power of the Wolf's Paw gem. Her powers include Heightened Reflexes and Senses, as well the the ability to manipulate shadows and blend in with them. During the invasion of Earth-1, Selena fights her doppelgänger Black Wolf and watches as Lilith kills her.
 * Stephen Amell as Oliver Queen/Green Arrow: A hero of Earth-1's Star City and leader of Team Arrow. He's the current mayor of Star City, the older brother of Elena Queen/Thunder Eagle, boyfriend of Andrea Rayne/Arctic Fox, and father of William Clayton. During the invasion of Earth-1, Oliver fights his doppelgänger Dark Arrow and ultimately kills him.
 * Nina Dobrev as Andrea Rayne/Arctic Fox: A hero of Earth-1's Star City and member of Team Arrow. She's the older sister of Rachel Rayne-Merlyn/Oracle and girlfriend of Oliver Queen/Green Arrow. Andrea is also the second-in-command of the Guardians, wielding the power of the Fox Head gem. Her powers include super stealth movements, heightened senses and reflexes, and the ability to perceive what isn't all there. During the invasion of Earth-1, Andrea fights her doppelgänger Shadow Fox and watches as Lilith kills her.
 * Victor Garber as Martin Stein/Firestorm: A member of the time traveling Legends, the husband of Clarissa Stein and father of Lilly Stein. He is one-half of the meta-human known as Firestorm, along with Jefferson "Jax" Jackson. While trying to escape from Earth-X, Martin is shot and mortally wounded. He later drinks a serum that separates his life-force from Jax's and dies from his wounds. After the defeat of the New Reich, the heroes hold a funeral for Martin and mourn him.
 * Caity Lotz as Sara Lance/White Canary: A member of the time traveling Legends and captain of the Waverider. She's a former member of the League of Assassins and Team Arrow, and is a skilled warrior. While in Central City for Cisco and Lorelai's wedding, Sara strikes up a brief fling with Alex Danvers of Earth-38, During the invasion of Earth-1, Sara fights the Reichsmen alongside Alex.
 * Dominic Purcell as Mick Rory/Heatwave: A member of the time traveling Legends and former partner of the late Leonard Snart/Captain Cold. He attends Lorelai's wedding to Cisco and acts as a brother-figure to her. During the invasion of Earth-1, Mick fights the Reichsmen alongside Leo Snart/Citizen Cold of Earth-X.
 * Franz Drameh as Jefferson "Jax" Jackson/Firestorm: A member of the time traveling Legends and one-half of the meta-human known as Firestorm, along with Martin Stein. While escaping from Earth-X, Jax's connection to Martin slowly begins to kill them. In order to save his life, Martin drank the cure created by Cisco, Caitlin, and Harry, and Jax stays by his side as he dies. After the defeat of the New Reich, Jax leads the memorial service for Martin and mourns him as the father he saw him as.
 * Sophia Bush as Ro-Aon/Rowan Eon/Tempus: A Drakonian, member of the time traveling Legends, and the second-in-command of the Waverider. She takes over as the captain while Sara, Martin, Jax and Mick attend Cisco and Lorelai's wedding. She later shows up with the rest of the team (Nate, Ray, Amaya and Zari) to save the captives at S.T.A.R. Labs and helps defeat Metallo.
 * Holland Roden as Sol-Gon/Emily Sparks/Solaris: A Drakonian and hero of Earth-38's National City, alongside her adoptive sister Alexa Sparks/Angel and Kara Danvers/Supergirl. Emily is also the girlfriend of Dr. Harrison Chambers and stays behind on Earth-38 while Kara and Alex go to Lorelai and Cisco's wedding on Earth-1.
 * Melissa Benoist as Kara Danvers/Supergirl: A Kryptonian and hero of Earth-38's National City, alongside her biological sister Alexa Sparks/Angel and Emily Sparks/Solaris. Kara attends Cisco and Lorelai's wedding on Earth-1, along with her adoptive sister Alex, in order to get out of their romantic funk. She fights with the rest of the heroes against the Earth-X invasion, and during the assault on Earth-1, Kara fights her doppelgänger Overgirl, alongside Archangel, Alexa's Earth-X doppelgänger.
 * Lucy Hale as Alexa Sparks/Angel: A Kryptonian and hero of Earth-38's National City, alongside her biological sister Kara Danvers/Supergirl and adoptive sister Emily Sparks/Solaris. Alexa is also the girlfriend of Winn Schott and stays behind on Earth-38 while Kara and Alex go to Lorelai and Cisco's wedding on Earth-1.
 * Chyler Leigh as Alex Danvers: A member of the DEO on Earth-38 and the older, adoptive sister of Kara Danvers/Supergirl. She's in a romantic funk after calling off her engagement and goes with Kara to Earth-1 for Cisco and Lorelai's wedding. While on Earth-1, she strikes up a brief fling with Legends member Sara Lance/White Canary. During the invasion of Earth-1, Alex fights the Reichsmen alongside Sara.
 * David Harewood as Director J'onn J'onzz/Martian Manhunter: The Director of the DEO on Earth-38 and a Green Martian.
 * Tom Cavanagh as Dr. Harrison Chambers: A scientist employed by the DEO as well as the Earth-38 doppelgänger of Harrison Wells. He is also the boyfriend of Emily Sparks/Solaris.
 * Jeremy Jordan as Winn Schott: A technician of the DEO on Earth-38 and best friend of Kara Danvers/Supergirl and the boyfriend of Alexa Sparks/Angel.
 * Chris Wood as Mon-El: A Daximite and ex-boyfriend of Kara Danvers/Supergirl.
 * Tom Cavanagh as Harry Wells: The Earth-2 doppelgänger of Harrison Wells, who works with Earth-1's Team Flash and has a romantic interest in Elizabeth Mendel. During the invasion of Earth-1, Harry pilots the Waverider and succeeds in using its weapons to destroy the Nazi's Wellenreiter. During the wedding ceremony, Harry stood up as one of Cisco's groomsmen.
 * Danielle Panabaker as Caitlin Snow/Killer Frost: A member of Earth-1's Team Flash who's alternate personality is a meta-human known as Killer Frost. Caitlin is a brilliant woman who helped engineer the Firestorm cure alongside Harry and Cisco. During the invasion of Earth-1, Killer Frost teams up with Zari and Vixen to disable the Wellenreiter before it's destroyed by the Waverider. Later, Caitlin mourns the death of Martin Stein.
 * Keiynan Lonsdale as Wally West/Kid Flash: A hero and member of Earth-1's Team Flash. He's the son of Joe West, younger brother of Iris West-Daniels, and brother-in-law of Theo Daniels. Wally only fights when the Nazi's first attack during the wedding ceremony, and after, he helps get his family to safety while the rest of the heroes fight the Reichsmen.
 * Jesse L. Martin as Joe West: A detective of Earth-1's Central City Police Department, the father of Iris West-Daniels and Wally West, foster father of Barry Allen/The Flash, father-in-law of Theo Daniels, and the boyfriend of Cecile Horton. During the first wedding ceremony, Joe walks Lorelai down the isle.
 * Danielle Nicolet as Cecile Horton: A district attorney of Earth-1's Central City and the girlfriend of Joe West.
 * Patrick Sabongui as David Singh: The captain of Earth-1's Central City Police Department as well as the boss and good friend of Joe West and Lorelai Snart.
 * Joey King as Frankie Kane/Magenta: A meta-human on Earth-1 and a close friend of Lorelai's who comes to Central City with her adoptive parents for Lorelai and Cisco's wedding.
 * Christina Brucato as Dr. Lilly Stein: The daughter of Martin and Clarissa Stein.
 * Isabella Hoffman as Clarissa Stein: The wife of Martin Stein and mother of Lilly Stein.
 * Colin Donnell as Tommy Merlyn/Prometheus: The Earth-X doppelgänger of the late Tommy Merlyn of Earth-1. He is a general of the New Reich serving under Chey-Gon alongside the Dark Guardians, Oliver Queen/Dark Arrow, Eobard Thawne/Reverse Flash, and Kara Danvers/Overgirl, He is the older brother of Dark Guardian Selena Merlyn/Lunar Wolf and is the first casualty of the war against the Earth-1 heroes.
 * Melissa Benoist as Kara Danvers/Overgirl: The Earth-X doppelgänger of Kara Danvers/Supergirl and one of the four generals serving under Chey-Gon, alongisde the Dark Guardians, Oliver Queen/Dark Arrow, Eobard Thawne/Reverse Flash, and Tommy Merlyn/Prometheus. Overgirl is also the biological sister of Archangel, a member of the Freedom Fighters and the adoptive sister of Lilith and an unnamed woman (presumably Alex Danvers' Earth-X doppelgänger). During the invasion of Earth-1, Overgirl fights her doppelgänger Supergirl and her own sister Archangel, and is ultimately killed by the latter via a Kryptonite dagger to the heart.
 * Tom Cavanagh as Eobard Thawne/Reverse Flash: A former member of Earth-1's Team Flash and currently one of the four generals of the New Reich serving under Chey-Gon alongside the Dark Guardians, Oliver Queen/Dark Arrow, Tommy Merlyn/Prometheus, and Kara Danvers/Overgirl. He is the ex-boyfriend of Elizabeth Mendel, and current lover of Chey-Gon/Lilith. During the invasion of Earth-1, Eobard fights Barry Allen/The Flash, and is spared the fate of his fellow Reichsmen.
 * Juliana Harkavy as Dinah Drake/Black Canary: A member of Earth-1's Team Arrow, who shows up to help battle the New Reich alongside her teammates Rene Ramirez/Wild Dog, Karina Knyazev/Salem, and Curtis Holt/Mr. Terrific. Together with her team, Heatwave, Killer Frost and Vibe, she fights the Dark Guardians and Dark Arrow, ultimately losing and being imprisoned in the S.T.A.R. Labs pipeline. After being freed by the remaining Legends, she's part of the team that defeats Metallo. During the invasion of Earth-1, she holds her own against the Reichsmen and later, sits with the rest of Team Arrow and watches as Diggle officiates Cisco and Lorelai's second wedding ceremony.
 * Rick Gonzales as Rene Ramirez/Wild Dog: A member of Earth-1's Team Arrow, who shows up to help battle the New Reich alongside his teammates Dinah Drake/Black Canary, Karina Knyazev/Salem, and Curtis Holt/Mr. Terrific. Together with his team, Heatwave, Killer Frost and Vibe, he fights the Dark Guardians and Dark Arrow, ultimately losing and being imprisoned in the S.T.A.R. Labs pipeline. After being freed by the remaining Legends, he's part of the team that defeats Metallo. During the invasion of Earth-1, he holds his own against the Reichsmen and later, sits with the rest of Team Arrow and watches as Diggle officiates Cisco and Lorelai's second wedding ceremony.
 * Alexandra Daddario as Karina Knyazev/Salem: A member of Earth-1's Team Arrow, who shows up to help battle the New Reich alongside her teammates Dinah Drake/Black Canary, Rene Ramirez/Wild Dog, and Curtis Holt/Mr. Terrific. Together with her team, Heatwave, Killer Frost and Vibe, she fights the Dark Guardians and Dark Arrow, ultimately losing and being imprisoned in the S.T.A.R. Labs pipeline. After being freed by the remaining Legends, she's part of the team that defeats Metallo. During the invasion of Earth-1, she holds her own against the Reichsmen and later, sits with the rest of Team Arrow and watches as Diggle officiates Cisco and Lorelai's second wedding ceremony.
 * Echo Kellum as Curtis Holt/Mr. Terrific: A member of Earth-1's Team Arrow, who shows up to help battle the New Reich alongside his teammates Dinah Drake/Black Canary, Rene Ramirez/Wild Dog, and Karina Knyazev/Salem. Together with his team, Heatwave, Killer Frost and Vibe, he fights the Dark Guardians and Dark Arrow, ultimately losing and being imprisoned in the S.T.A.R. Labs pipeline. After being freed by the remaining Legends, he's part of the team that defeats Metallo. During the invasion of Earth-1, he holds his own against the Reichsmen and later, sits with the rest of Team Arrow and watches as Diggle officiates Cisco and Lorelai's second wedding ceremony.
 * Russell Torvey as Ray Terill/The Ray: Formerly of Earth-1, and now a member of the Earth-X Freedom Fighters, who meets a group of Earth-1 heroes while in a concentration camp. After being rescued by fellow Freedom Fighters, Leo Snart/Citizen Cold and Dante Ramon/Hardline, he agrees to help the Earth-1 heroes fight the Reichsmen. During the invasion of Earth-1, Ray holds his own against the Reichsmen, and later, sits with Leo, Dante, and Xera as they watch Cisco and Lorelai's wedding before returning to Earth-X with Dante and Xera.
 * Colton Haynes as Roy Harper/Red Arrow: The Earth-X doppelgänger of Roy Harper/Arsenal of Earth-1, and a member of the Freedom Fighters, who meets a group of Earth-1 heroes while in a concentration camp. He forms an instant connection with Elena Queen/Thunder Eagle, due to her being the doppelgänger of the woman he loves. After being rescued by fellow Freedom Fighters Leo Snart/Citizen Cold and Dante Ramon/Hardline, he takes a few bullets to protect Elena and later dies at the Freedom Fighter base in Star City.
 * Paul Blackthorne as Sturmbannführer: The Earth-X doppelgänger of Quentin Lance of Earth-1 and a member of the New Reich under the four generals; Dark Arrow, Prometheus, Overgirl and Reverse Flash, the Dark Guardians, and the Dragon Queen, Chey-Gon/Lilith.
 * Wentworth Miller as Leo Snart/Citizen Cold: The Earth-X doppelgänger of the late Leonard Snart/Captain Cold of Earth-1, and a member of the Freedom Fighters. He, along with Dante Ramon/Hardline, rescues the Earth-1 heroes. Roy and Ray from the concentration camp and takes them back to the Freedom Fighter base in Star City, where he takes a moment to grieve the death of Roy Harper/Red Arrow. Leo decides to go to Earth-1 and fight against the Reichsmen, along with Ray, Dante, and Xera. After the defeat of the Reichsmen, Leo attends Lorelai and Cisco's wedding, where he walks his Earth-1 sister down the isle. Leo is the older brother of the late Lisa Snart and Dark Guardian Lorelai Snart/Black Grizzly, the boyfriend of Ray Terrill/The Ray, and the unofficial "adoptive" brother of Lorelai Ramon/Ice Princess of Earth-1.
 * Nick Gonzales as Dante Ramon/Hardline: The Earth-X doppelgänger of the late Dante Ramon of Earth-1 and member of the Freedom Fighters. He, along with Leo Snart/Citizen Cold, rescues the Earth-1 heroes. Roy and Ray from the concentration camp and takes them back to the Freedom Fighter base in Star City, where he tries and fails to save the life of Roy Harper/Red Arrow. Dante decides to go to Earth-1 and fight against the Reichsmen, along with Ray, Leo, and Xera. After the defeat of the Reichsmen, Dante attends Lorelai and Cisco's wedding before returning back to Earth-X with Ray and Xera. Dante is the brother of the late Cisco Ramon/Vibe of Earth-X.
 * Bex-Taylor Klaus as Cindy Simone: The Earth-X doppelgänger of Cindy "Sin" Simone of Earth-1, a civilian member of the Freedom Fighters and was the best friend of Roy Harper/Red Arrow.
 * Jeremy Jordan as General Winn Schott: Winn's Earth-X doppelgänger, the leader of the Freedom Fighters and the husband of Xera Zor-El/Archangel.
 * Lucy Hale as Xera Zor-El/Archangel: Alexa's Earth-X doppelgänger and member of the Freedom Fighters. She's the biological sister of Kara Danvers/Overgirl and the wife of General Winn Schott. She, along with Leo, Ray, and Dante, travels to Earth-1to fight the Reichsmen. During the invasion of Earth-1, Xera fights Overgirl, alongside Supergirl of Earth-38, and she succeeds in killing Overgirl with a Kryptonite dagger to the heart. After the defeat of the Reichsmen, Xera attends Lorelai and Cisco's wedding before returning back to Earth-X with Ray and Dante.
 * Brandon Routh as Ray Palmer/The Atom: A member of the time traveling Legends and former member of Team Arrow. He shows up before the final battle against the Reichsmen, helping Rachel, Iris and Theo save Elizabeth from Eobard. After the defeat of the Reichsmen, Ray attends Martin's funeral and later, sits with the rest of the Legends as Diggle officiates Cisco and Lorelai's second ceremony.
 * Nick Zano as Nate Heywood/Steel: A member of the time traveling Legends, who shows up to release the rest of the heroes from the S.T.A.R. Labs Pipeline, and later helps them defeat Metallo. After the defeat of the Reichsmen, Nate attends Martin's funeral and later, sits with the rest of the Legends as Diggle officiates Cisco and Lorelai's second ceremony, during which he shares a longing look with Rowan.
 * Maisie Richardson-Sellers as Amaya Jiwe/Vixen: A member of the time traveling Legends, who shows up before the final battle against the Reichsmen. Vixen, along with Zari, takes care of the soldiers guarding S.T.A.R. Labs before helping to defeat Metallo. During the battle with the Reichsmen, Vixen goes with Zari and Killer Frost aboard the Wellenreiter and disables its safeguards before being breached back to the Waverider by Vibe as the Wellenreiter is destroyed. After the defeat of the Reichsmen, Amaya attends Martin's funeral, and later, sits with the rest of the Legends as Diggle officiates Cisco and Lorelai's second ceremony.
 * Tala Ashe as Zari Tomaz: A new member of the time traveling Legends who wields the powers of the Air Totem. Zari shows up before the final battle against the Reichsmen, aiding Vixen as they take care of the soldiers guarding S.T.A.R. Labs before helping to defeat Metallo. During the battle with the Reichsmen, Zari goes with Vixen and Killer Frost aboard the Wellenreiter and disables its safeguards before being breached back to the Waverider by Vibe as the Wellenreiter is destroyed. After the defeat of the Reichsmen, Zari attends Martin's funeral, and later, sits with the rest of the Legends as Diggle officiates Cisco and Lorelai's second ceremony.
 * Amy Louise Pemberton as Gideon: The interactive artificial consciousness programmed to operate the Waverider 's critical systems and to aid the Legends on missions.
 * Susanna Thompson as Wellenreiter A.I.: The interactive artificial consciousness programmed to operate the Wellenreiter's critical systems.
 * David Ramsey as John Diggle/Spartan: A hero on Earth-1 and a member of Star City's Team Arrow. He only appears in the final act, brought to Central City by Barry Allen/The Flash and agrees to officiate Cisco and Lorelai's second wedding ceremony, which is witnessed by Team Flash, Team Arrow, the Legends, Alex and Kara of Earth-38, and Leo, Ray, Dante and Xera of Earth-X.

Misc. Trivia

 * Earth-X is a world where Germany won World War II and Green Arrow and his team, The Flash and his team, Supergirl and Angel are evil.
 * In DC and Drakonia Comics continuity, the Nazis play the same role on Earth-X as they do in the Arrowverse. However, it is considered a part of the main 52 universes in the multiverse, rather than something outside of it, with its alternate versions in the continuity being known as Earth-10 (though it is still called "Earth-X", but in this case it is because the "X" is the Roman numeral of 10).
 * Earth-X developed some form of a meritocracy.
 * It's stated that there were 52 Earths in the multiverse. Harry revealed that there are actually 53 Earths, but Earth-X is so horrible that no one goes there and therefore it does not have a formal designation. However, it is not indicated how or when Harry came to possess this information.
 * This is contradictory to Martin Stein's statement in "Flash of Two Worlds" and Harry's statement in "The Final Race" that there are "infinite" Earths. Although, it's possible that Harry simply meant that there were 53 known Earths in the multiverse.
 * Earth-X is nicknamed “Planet Nazi” by Mick Rory and “Nazi Earth” by Cisco Ramon and Ray Terrill.
 * According to Tommy Merlyn/Prometheus, life on Earth-X has no choices; it's all about following orders.
 * There are two similarities between this crossover and the previous crossover event:
 * The Dominators wanted Barry to surrender himself, while the Earth-X Nazis (specifically Lilith and the Dark Guardians) wanted Elizabeth to surrender herself.
 * Both the Dominators and the Earth-X Nazis invaded Central City on Earth-1.
 * This is the first crossover event:
 * To not reference Oliver shooting Barry which happened in the Guardians of Central City episode "Flash vs Arrow"
 * To feature Iris (Candice Patton), Theo (Paul Wesley) and a version of Harrison Wells (Tom Cavanagh) in all acts. Previously, they had only appeared in The Flash based portions of the crossovers.
 * Where John Diggle/Spartan (David Ramsey) didn't appear in every act.
 * Where Cisco Ramon/Vibe (Carlos Valdes) didn't appear in every act.
 * Where Ro-Aon/Rowan Eon/Tempus (Sophia Bush) didn't appear in every act.
 * To feature Alex Danvers (Chyler Leigh)
 * Where The Flash based series didn't serve as the first part of the event.
 * John Diggle/Spartan, Dinah Drake/Black Canary, Rene Ramirez/Wild Dog, Karina Knayzev/Salem, Curtis Holt/Mr. Terrific, Amaya Jiwe/Vixen, Nate Heywood/Steel, Rowan Eon/Tempus, Ray Palmer/The Atom, and Zari Tomaz were the only heroes who appeared in the crossover not in attendance at Cisco and Lorelai's first wedding ceremony.

Prologue

 * This act is based on the first few scenes of Crisis on Earth-X part 1 (Supergirl 3X08)
 * The first opening scene is of the Dark Guardians and Dark Arrow taking the Freedom Fighters outpost
 * The second scene is the different montages of the various heroes in their respective cities (Team Flash and Elena Queen/Thunder Eagle in Central City fighting King Shark, Team Arrow in Star City fighting unnamed ninjas, and Supergirl, Angel and Solaris fighting a Dominator in National City), and later goes into Alex, Kara, Alexa, Emily, Winn and Harrison in Kara's apartment as they talk about Cisco and Lorelai's wedding invite.

The Rehearsal Dinner

 * This act is based on the first half of Crisis on Earth-X part 1 (Supergirl 3X08)

Nazi Wedding Crashers

 * This act is based on the second half of Crisis on Earth-X part 1 (Supergirl 3X08)
 * This act title is a reference to the 2005 film "Wedding Crashers"

Who's Under the Masks

 * This act is based on the first half of Crisis on Earth-X part 2 (Arrow 6X08)

Battle Royale on Earth-1

 * This act is based on the second half of Crisis on Earth-X part 2 (Arrow 6X08)

Welcome to Earth-X

 * This act is based on the first part of Crisis on Earth-X part 3 (The Flash 4X08)

The Freedom Fighters

 * This act is based on the second part of Crisis on Earth-X part 3 (The Flash 4X08)

Getting Back Home

 * This act is based on the third part of Crisis on Earth-X part 3 (The Flash 4X08)

The Calvary

 * This act is based on the first part of Crisis on Earth-X part 4 (Legends of Tomorrow 3X08)

Guardians vs Dark Guardians

 * This act is based on the second part of Crisis on Earth-X part 4 (Legends of Tomorrow 3X08)

IceVibe Happily Ever After

 * This act is based on thelast few scenes of Crisis on Earth-X part 4 (Legends of Tomorrow 3X08)
 * The acts title references the ship name for Lorelai Snart/Ice Princess and Cisco Ramon/Vibe and the classic line from every fairy tail "...happily ever after."