Return Of An Old Friend is a two-part episode in the first season of Digimon Mighty Squadron. This content is used from the Power Rangers wiki.
It's Parents' Day at Tokyo, & four of the DigiDestined—Taylor, Spencer, Carly, & Maggie—are enjoying themselves with the rest of the student body of Tokyo High at the Youth Center.
Meanwhile, Lilithmon is planning her hugest scheme yet, when she orders Wisemon to create the Drimogemon, who can hypnotize its victims with toxic gas emitted from its nostril. When the DigiDestined head out to look for more refreshments for the Parents' Day celebration, Lilithmon uses the distraction to trap all in the Tokyo Youth Center in another dimension in the Digital World, just as Nicky—the only DigiDestined not present at the party, enters & finds the Youth Center deserted. At that point, he is overcome by Drimogemon's hypnotic gas, & while under Lilithmon's control, he infiltrates the Command Center, shuts down Kokuwamon, & steals the DigiDagger—the only thing capable of summoning & controlling Coredramon.
The DigiDestined are alerted to Nicky's theft by Seraphimon, summon their Digimon, & teleport to the Dark Dimension, where Nicky is just about to hand the DigiDagger to MadLeomon. MadLeomon keeps the four DigiDestined busy with a contingent of Claymon, long enough to take possession of the Dagger & teleport back to Earth. Nicky is set free from Drimogemon's mind-control gas, & he summons his Digimon, Triceramon, & teleports with his teammates back to Tokyo, but not in time to keep MadLeomon from summoning Coredramon & sending it in to attack Tokyo. The DigiDestined summon DinoOmnimon to hold Coredramon at bay, but the former is slammed & severely damaged by the latter. The DigiDestined leap off of DinoOmnimon's shoulders in time to be informed by MadLeomon to give up their digivices or lose their parents forever. With no choice but to save their parents' lives, the DigiDestined, one by one, hand over their digivices, placing them inside an ornate treasure box held by MadLeomon. However, MadLeomon only wanted the DigiDestined unable to stop Lilithmon from conquering the world, & with the digivices now in his possession, he believes, nothing can stop her now.
However, at the Command Center, the DigiDestined discover that Taylor did not hand over all the digivice. He still has the green digivice, which Alex gave to him when he was in danger of losing his powers to Lilithmon. And meanwhile, back at the deserted Youth Center, Alex has just entered the main hall, confused when he finds it empty.
The DigiDestined, with Seraphimon's help, make a plan to retrieve their parents from Lilithmon's Dark Dimension, but first, they will need their digivices back. With only one digivice left—Alex's digivice—the DigiDestined have no choice but to ask their old friend for help. Kokuwamon teleports Alex back to the Command Center, but Alex wonders how he will be able to help with his powers depleted. Seraphimon has an idea, but it will be very risky. He intends to infuse Alex with his own energy, giving him a clone of Coredramon for a time, but, as the DigiDestined warn him, the power will not last long, & if Seraphimon drains too much of his energy trying to restore Alex's powers, he will cease to exist.
While MadLeomon reawakens the real Coredramon's powers to finish destroying Tokyo, Seraphimon implements his plan, nearly draining himself of his own life force, but temporarily restoring Alex's powers in the process. Alex & the Coredramon clone teleports to MadLeomon's location & confronts him, but the man-beast Digimon merely sends Claymon to deal with Alex & weaken his powers until they are depleted again.
After a harrowing battle, Alex manages to retrieve the DigiDagger & regain control of the real Coredramon, but Lilithmon sends Minervamon to help MadLeomon destroy the Digimon. As giants, the two warrior Digimon battle Coredramon until they realize that they have left the DigiDestined's digivices unguarded. Back at the Command Center, Seraphimon has drained away all of his life force trying to maintain Alex's powers. Meanwhile, just as Alex is within an inch of powering down permanently, he ekes out a victory by retrieving the digivices & is teleported back to the Command Center just as a Claymon is about to strike him down. When Alex reaches the Command Center, the physical & mental strain of maintaining his powers has taken its toll on him, & he passes out.
After the DigiDestined make certain that Alex is okay, they work on a plan to try to restore Seraphimon, & Nicky & Kokuwamon discover that the DigiDestined could restore Seraphimon by infusing him with energy from their digivices. They attempt this, & to their good fortune, the energy infusion does work, just as Lilithmon sends Drimogemon to attack the rock quarry outside the city. Seraphimon informs the team that by destroying Drimogemon, the DigiDestined's parents will be returned to Earth from the Dark Dimension, so they summon their Digimon & teleport to the rock quarry to confront Drimogemon. However, Drimogemon uses his hypnotic gas to mind-control four of the DigiDestined into attacking Maggie & Pteramon.
Back at the Command Center, Kokuwamon & Seraphimon discover that Alex's body has been electrically charged by the force field surrounding the digivices. That energy has restored his powers temporarily, & when Kokuwamon hands Alex his digivice, he summons Coredramon & sends out laser blasts that incapacitate Drimogemon, setting the four DigiDestined he had put under his control free. Enraged, Lilithmon throws her wand down to Earth, making Drimogemon grow. Alex uses his DigiDagger to DigiGrow Coredramon while the other DigiDestined summon DinoOmnimon. A harrowing battle ensues before the DigiDestined call forth KingBrachiomon & form CoreOmnimon, which disposes of Drimogemon with its finishing blast.
After the battle, Seraphimon is pleased to inform the DigiDestined that with Drimogemon destroyed, the citizens of Tokyo have been returned to their own dimension, with no memory of what transpired. Taylor & the other DigiDestined celebrate Alex's return, but Kokuwamon & Seraphimon warn that Alex's powers are still temporary, & they could fail him at any time, but Alex chooses to continue his work as a DigiDestined—even if it means someday he may never be one again.
The DigiDestined hurry back to the Youth Center & express their love for all their parents, & Maggie (whose parents are divorced) decides to introduce her mother & father to Alex, just as Brick & Stick start a food fight in the Youth Center. Soon all the grown-ups join in, forcing the DigiDestined to retreat to the entryway, laughing over the fact that there is still a little kid in all their parents.