Doomsday is a two-part episode of the first season of Digimon Mighty Squadron. This content is used from the Power Rangers wiki.
The day begins at Tokyo High School, as most episodes of this season do. Maggie reads in the paper to her friends—Taylor, Spencer, Carly, & Nicky—that the Madame Mayor of Tokyo has declared an annual "Digimon Day" on this day.
Meanwhile, Lilithmon is planning her biggest scheme yet. She plans to bring her entire Lunar Palace from the moon & land it on the Earth. On Earth, Lilithmon's powers will be increased exponentially, & she will be able to summon an evil War Digimon that only made one appearance 10,000 years ago—the dreaded Craniamon. As added insurance, she plans to trap all of Tokyo's populace—excluding the DigiDestined—in another dimension in the Digital World.
Back on Earth, in Tokyo Park, a myriad of citizens have shown up for a special appearance by the DigiDestined, but Brick & Stick show up as the "Incredible Brickster" & "Super Stick". While showing off to the crowd, they end up making total fools of themselves, as always. Meanwhile, Lilithmon has just landed her Lunar Palace on Earth, & is putting her plan into action. The plan works almost perfectly, but Seraphimon & Kokuwamon are alerted to Lilithmon's arrival. As the DigiDestined alert Seraphimon of the situation & its gravity, Seraphimon tells the DigiDestined that Lilithmon has arrived on Earth & awakened Craniamon, the evil War Digimon.
The DigiDestined summon their Digimon & teleport to downtown Tokyo & summon DinoOmnimon to fight Craniamon. DinoOmnimon is beaten badly, so they summon Coredramon for extra power. Then the Digimon change battle modes, & BattleCoredramon, fighting alongside Tyrannomon, fend off Craniamon. However, the DigiDestined are still losing badly, until Seraphimon summons KingBrachiomon. The Digimon form CoreOmnimon & hops on KingBrachiomon, who finishes off Craniamon, but the evil Digimon's head remains intact. Lilithmon uses her new magnified power to send KingBrachiomon to its doom in a giant sinkhole. Then she summons back Apocalymon to revive Craniamon.
While the DigiDestined are working as fast as they can to recharge the Digimon, Craniamon begins another assault on the deserted city of Tokyo. Taylor knows that the Digimon aren't fully recharged yet, but he decides that the DigiDestined have to stop Lilithmon. He suggests that the DigiDestined take the Digimon while they are halfway recharged, but Seraphimon advises against it—the DigiDestined could end up destroying their powers. But the other DigiDestined agree with Taylor, & Kokuwamon sets the coordinates. The DigiDestined summon their Digimon & take DinoOmnimon into the city to fight off Craniamon, but DinoOmnimon gets wrecked & loses an arm in the process. Taylor summons Coredramon, but it does no better against Craniamon & gets half its tail sliced off. After being overloaded with magic from Lilithmon's staff, the Digimon lose all power & seem to disintegrate as the DigiDestined evacuate, ending up in the deserted Tokyo Park. Taylor tries to call Seraphimon, but the signal to the CCCs is jammed. When Nicky says he can alter the frequency modulation on the communicators, the DigiDestined race to Nicky's lab.
Meanwhile, Lilithmon decides that the DigiDestined must be destroyed before they can restore their Digimon's energies, so she sends MadLeomon & some Claymon to finish off the teens. At the Command Center, Kokuwamon gives Seraphimon a status report & then discovers some shocking information—with the Lunar Palace on Earth, Lilithmon has left information about her Digimon vulnerable to computer access. Kokuwamon takes advantage of this, & just as the DigiDestined fix their CCCs & teleport to the Command Center, Seraphimon informs the teens that Craniamon must adjust its computers to compensate for battle with a new opponent. The quicker & the more frequently the DigiDestined change Digimon Battle Modes, the weaker Craniamon will become as it attempts to adjust to its new enemy.
With this new information & the Digimon fully re-energized, the DigiDestined summon their Digimon & teleport to the city, DigiGrow their Digimon, & attack individually at first, then use DinoOmnimon & BattleCoredramon. All three strategies fail, but not before Coredramon manages to destroy Craniamon's double-sword. After one final blast from Apocalymon, the DigiDestined summon KingBrachiomon & form CoreOmnimon. On this note, Craniamon freezes up completely, leaving it helpless when CoreOmnimon finishes it off. Lilithmon & her minions yell at each other, blaming everyone else, before escaping back to the moon. The Tokyo citizens are restored to their own dimension, & the Mayor tells Brick & Stick to get off the stage, while the DigiDestined & their Digimon approach, being greeted by several citizens on the way to the stage. Several children boast about their favorite Digimon, & then Alex (making a cameo appearance) hints that all the Digimon are awesome. The Mayor praises the DigiDestined for saving their city & the world several times, & the audience cheers for them.
Back at the Command Center, Seraphimon also praises the DigiDestined for their dedication & hard work to saving the world & offers them a chance to return to their normal lives, but they make a unanimous decision to remain with their Digimon forever.