With the annoucement of Crisis On Infinite Earths for Fall 2019, my mind just started churning with ideas on what can be done and the ultimate aftermath that can change the Arrowverse forever. This is real rough and brief. So Lets begin
SuperGirl: Crisis On Infinite Earths Part 1
The First scene we witness is the Monitor watching over all the different Earths in his dimension. Then the arrival of his counter-part The Anti-Monitor arrives and drains his energy leaving The Monitor weak. Monitor escapes but the Anti-Monitor begins his conquest of all reality. Meanwhile on Earth-38 Kara deals with technology going haywire and wierd disturbances. Somehow Brainey has been causing the techno disturbances and turns on Kara and the DEO. Brainey reports to Lex Luthor of Earth-11 (Smallville Universe). The Monitor arrives weaked and informs Kara of the Crisis that will destroy all realities. He uses some of his remaining abilities to pull Clark Kent from Earth-11 and Clark Kent from Earth-90 (Lois and Clark Universe) to help deal with the coming crisis. Kara gets Barry and Cisco from Earth-1 to help. Lex from Earth-11 links up with the Lex of Earth-38 to harvest the technology of Brainaic from both Earth's to create a new Brainaic (played by Smallville Brainaic). Clark from Earth-38 joins in to help stop the Brainaic but the Anti-Monitor reveals himself and says Earth-38 was a testing ground. Earth-1 will be the start of his conquest. Earth-11 and Earth-90 residents return to their reality to prepare while Kara, Barry, Cisco, Clark and Jon head to Earth-1 to mount a defense against The Anti-Monitor
The Flash: Crisis On Infinite Earths Part 2
Barry and the rest return to Earth-1 with a weaken Monitor to STAR Labs. Monitor explains that he was testing the heroes the year prior for Anti-Monitor arrival. He wishes to decimate the multiverse and rule over them, Earth-1 being the Prime-Earth will be the battlegrounds for the entire multiverse. The team encounter Anti-Monitor with Flash, Superman, Supergirl, Kid Flash, Martian Manhunter, Killer Frost and Vibe but are no match. Earth-90 Flash comes and rescues them bringing along Vixen and Star-Girl. After regrouping the team are told by The Monitor that because this Earth's Central City has been the epicenter of Dark Matter The Anti-Monitor wants to harness the energy to convert to Anti-Matter the source of his power. Iris finds a device at Argus facility that The Anti-Monitor could use and they race to stop him with help from Diggle and Oliver. They do and try and use the device to take Anti-Monitor's power and give it back to The Monitor. Anti-Monitor appears and reveals that STAR Labs is the epicenter and activates the device to soak up residual energy from the city but before he can leave Monitor is able to retrieve some of his powers back weakening Anti-Monitor but knocking Monitor out. Cisco and Caitlyn deduce that the leading expert in Anti-Matter conversion is in Gotham City, Dr. Kell Mossa
The BatWoman: Crisis On Infinite Earths Part 3
Barry, Oliver, Kara, and Clark arrive in Earth-1 Gotham City and update Kate Kane on the situation. Kate helps them locate Dr. Kell Mossa but the information has been deleted by Bruce Wayne. Apparently Bruce is back in Gotham is already meeting with Dr. Kell Mossa to get him to build a device. Kate finds Bruce but he is acting different, its revealed later that the Bruce in town is from Earth-2 and is called Owlman, a ruthless vigilante who rules Gotham with terror and fear. Anti-Monitor plucked him from Earth-2 to secure the device he needs. The Heroes tangle with Owlman but despite the power advantage Owlman is a step ahead of them until Black Siren appears and reunites with her old friend. The reunion is cut short with the arrival of the Earth-1 Batman. Owlman escapes without Dr. Mossa which greatly disappoints Anti-Monitor who then brings in Psycho Pirate to be his new emissary and retrieve the doctor. The heroes hold up in Wayne Tower and discuss if Dr. Mossa can construct a device to convert Anti-Monitor Anti-Matter into Matter canceling him out. Dr. Mossa believes he can do it but needs a lab, Barry suggest STAR Labs but Oliver suggest a blacksite in Star City for Argus. As the team tries to leave Psycho Pirate attacks the tower, even using Kryptonite weapons to take care of Clark and Kara. The team escapes to Star City while the Anti-Monitor tells Psycho Pirate to find Lyla Diggle
Arrow: Crisis On Infinite Earths Part 4
The heroes arrive in Star City at a Argus Blacksite. Dr. Mossa has the heroes find specific devices to help him with the Anti-Matter Converter. Meanwhile Psycho Pirate finds Lyla and bring her to a weaken Anti-Monitor. He says that in another Earth she is his protegee The Harbringer, his most loyal servant, he merges the personas into Lyla turning her into Harbringer and to inflitrate the heroes to get Dr. Mossa. Felicity finds out that one of the compenents needed for the device doesnt exist on this Earth but Cisco vibes to concentrate on a Earth that may have it and its Earth-11. Oliver, Felicity, Barry, Kara, Kate and Cisco end up in Earth-11 Star City where they encounter the Oliver Queen of that Earth (played by Smallville Oliver Queen) At first he doesnt believe whats happening especially seeing Barry and Kara but eventually he helps them find the device but Lyla follows them and causes trouble. They secure the compenent and race back to Earth-1 with Earth-11 Oliver but Lyla decides to kill Dr. Mossa from completing the device instead. Afterward The Monitor awakens and tells them of Earth-14 where another Dr. Mossa resides in that can finish the device. The Anti-Monitor already decides that as well and sends Lyla to Earth-14 which is Freeland/Black Lightning Earth.
Black Lightning: Crisis On Infinite Earths Part 5
Freeland experiences freak lighting storms that are effecting both Jefferson and Jennifer. Meanwhile Lyla is looking for Dr. Mossa of Earth-14. Dr. Mossa works out of college in Freeland that is attacked by Lyla. Jefferson arrives and is overpowered by Lyla until Oliver, Barry and Kate arrive to help him. Dr. Mossa is not at the school so both parties leave. Barry explains to Jefferson on Multiverse Theory and the threat of Anti-Monitor in which Jefferson agree's to help in order to save his family and city. Lyla encounters Tobias trying to find Dr. Mossa, who reluctantly helps Lyla due to her power. Dr. Mossa location is found by both Lyla and the heroes and race to find him before Lyla does. A battle occurs but Kara comes and saves the team and secures Dr. Mossa. Lyla takes Jennifer as her power could be used to help Anti-Monitor. Jefferson agrees to go to Earth-1 to rescue his daughter and save the Multiverse. When they arrive on Earth-1 the Argus facility has been invaded by Psycho Pirate and with him is Reverse Flash, Malcolm Merlin, Damien Darhk Lex Luthor, and Brainaic. Before they can react the Waverider arrives and scopes them up with the rest of the team inside. Sara says Pyscho Pirate arrived with the villains and took the pieces and The Monitor
DC's Legends Of Tomorrow: Crisis On Infinite Earths Part 6/Finale
The Legends, Team Flash, Team SuperGirl, Team Arrow, Batwoman and Black Lightning regroup to figure out a way to stop Anti-Monitor. John wants to get Lyla back and Jefferson is focused on his daughter so both decide to reach out to Lyla for a trade. At the meet John tries to reach Lyla but it falls on deaf ears as Anti-Monitor arrives to claim Dr. Mossa. The Heroes ambush Anti-Monitor as a trap was laid to find a way into Anti-Monitor's subspace. Ray and Nate end up sneaking in and finding Jennifer and The Monitor but Pyscho Pirate causes some trouble but is defeated. Ray grabs the device and rescue Jennifer but The Monitor is in bad condition, he can no longer hold off on Anti-Monitor's power increase and passes out givng all his power to Anti-Monitor who takes back Dr. Mossa and probes his mind to put together the device. He then converts Jennifer's power and the Dark Matter into Anti-Matter increasing his power. He then causes a massive wave which begins shifting and changing reality. Some of the Earth's previously visted begin to merge into Earth-1 causing massive distrubances in the skies and weather. The heroes retreat into the Waverider to regroup but all seems lost until previous heroes from different Earth's appear in the Waverider to help. The Monitor is still in a coma so Cisco vibes him and the Monitor fortells Anti-Monitors goal to merge all the Earth by using Earth-1 as the foundation which will destroy reality, a few worlds merge wont do anything but all would be catastrophic. Sara, Barry, Oliver, Kara, Kate and Jefferson decide amongst each other a contingency after hearing the Anti-Monitor plan. The heroes put on a last stand in Star City while Sara, Barry, Oliver, Kara, Kate, Constantine and Jefferson force a way into Anti-Monitor's subspace where they look for the Book Of Destiny. Constaintine uses to put a protective force around Earth-1,38, and 14 and unlock bring heroes from those Earth's to help. They also restore The Monitor's powers, meanwhile the heroes get another win when John reaches Lyla who betrayes The Anti-Monitor by weakening his powers. This gives the heroes what they need to stop Anti-Monitor and finish him. The Monitor informs the heroes that the tunnel they produced for the other Earth's has caused a massive imbalance. Sara, Barry, Oliver, Kara, and Jefferson realized that in order to make sure reality is protected was to bring together the Infinite Earth's mightest heroes from their Earths. They knew the outcome would be to fuse the three earth's together. The Monitor tells them that the 6 of them to include Kate Kane will be the only ones who will know about the merger. Once The Monitor leaves and threat over everyone except those 6 are unaware that three Earth's had merged and that National City, and Freeland are apart of the now called Earth-Prime.
Pre-Credit Scene
A news anchor is going over his notes for broadcast when he see's a clip of the heroes fighting Anti-Monitor. He then activates a communcation device and says "The Heroes of this Earth have united, Now is the perfect time to turn Humanity against them, all for the glory of DarkSied". We then see the name of the show Gripping News with Gordon Godfrey...
Gods and Monsters (based on The Legends Crossover Event of 1986