A long time ago in a galaxy far, far away....
Well, not so long ago....
The balance of the multiverse is at stake. After the defeat of the menace only known as Virus, new threats have begun to invade various dimensions, hoping to gain ultimate power over existence.
These villains have set their sights on eliminating the Legacy Squad, whose influence is praised everywhere. To accomplish this goal, they have set up schemes to take advantage of what exists in the Tooniverse's various territories.
The supreme goddess Oceanbird, realizing that the Legacy Squad will need assistance, has found some new heroes to join them on their mission to save their dimensions once more....
The prologue begins in space, as a strange starfighter heads towards a similarly strange space station. Count Dooku enters the hangar, where he meets up with General Grievous. The two of them head to the throne room, where Mace Windu is being held hostage. Dooku asks him where Anakin Skywalker is, but Mace refuses to give any information. Just then, the Turner Portal passes by before fading away. Dooku realizes that there is a discovery to be made... in another dimension...
Meanwhile, in Huber, Dexter is celebrating his 12th birthday. Everyone gives him their presents, and he goes to get the cake -- but there are portals opening up! Various old cartoon gags drop in, with Bugs Bunny and Daffy Duck coming down with them. Beau asks them what they're doing there, and Daffy tries to explain, but to no avail. Suddenly, a green portal appears and sucks Dexter in.
Dexter lands in a dark city, which is dimly lit with green gems. Three soldiers that look like Gumball Watterson, Yumi Yoshimura, and Robot Jones grab him and take him to an ominous castle, where they come across the ruler of this dimension: Peridot. She orders the three of them to take Dexter to the facilities, but the seemingly evil clone of Yumi does a guitar riff, releasing high-frequency sound waves. The clones of Yumi and Gumball reveal that they are not clones, but they are Yumi and Gumball. The real Robot Jones shows up behind them, and Peridot commands a squadron of robots to capture the four heroes. Dexter, Yumi, Gumball, and Robot fight the enemies and eventually manage to escape via dimension ship.
Acquired Characters: Dexter, Yumi, Gumball, Robot Jones
Beau enters Professor Utonium's lab, where Dee Dee has grabbed the bottle of Chemical X. She says she doesn't need him sticking up for her anymore, and smashes the bottle, releasing the black clouds inside. She later emerges from the Powerpuff Girls' house as Diva Dynamite, seeking to save Dexter. Diva Dynamite opens a portal and enters it, and Beau decides to go home and try to get some sleep.
In Beau's dream, Julie Hinikawa speaks to him telepathically. She explains that she has accidentally created an alternate reality in which Peridot rules with an iron fist. Julie is still trying to figure out what to do to stop her, and says she'll speak to Beau later. Beau is about to say he cares about her, but she fades away before he can finish.
Beau wakes up and finds Dexter's interdimensional ship waiting for him and the Powerpuff Girls. Yumi tells them that Ami is waiting at the temple owned by the ruler of the Tooniverse... Oceanbird. They go through a portal and reach the temple, where Oceanbird explains that the new threat -- Peridot's empire -- requires some new heroes to go up against it. She shows the heroes four holograms -- one with Mordecai and Rigby, one with Robotboy, another with four minifigure-like ninja, and the last one with a superhero wearing a dark suit. Robot Jones immediately identifies the last hologram as Batman, and gets all giddy with excitement. Before the heroes leave, Oceanbird tells another new hero to go with them -- TOM, from the now obliterated Toonamiverse.
During a trip through the space-time continuum, a new team of Thrownaways captures the group. Their leader -- a humanized Bullet from The Powerpuff Girls -- sends Robot Jones and Puffy AmiYumi to Peridot's dimension, banishes the others to The Park, and keeps Dexter and Tom for herself.
Acquired Characters: Dee Dee, Beau, Blossom, Bubbles, Buttercup, Ami, Bugs, Daffy
Peridot City II
General Jones explains the backstory of Peridot's empire: Peridot had destroyed Yellow Diamond a while back, and she created evil Jones units to serve as the basic soldiers for her army. They destroyed humanity and left their mistress to rule the world. The real Robot Jones tries to convince the general to break away from the empire, but he denies and blasts his bulb off.
Yumi and Ami manage to struggle out of the MNDRK units' grasp and fight them. Meanwhile, Bubbles comes across a mysterious room filled with battle droids, and hears beeping noises that come much closer until R2-D2 rolls over. C-3PO follows him there, and meets Bubbles, Ami, and Yumi. They pick up Robot Jones and escape through a portal -- but not before the battle droids wake up and fight them.
Yumi, Ami, and Bubbles follow the droids into the Mos Eisley spaceport, where they find the spy Oceanbird had mentioned earlier. Yumi challenges the spy to a battle, and she wins said battle... but the spy removes their mask, revealing a girl. Kelsie O'Fallon introduces herself, and explains that Peridot didn't wipe out ALL of humanity. Her father founded a resistance force twenty years after she took over and became immortal, but Peridot killed him in a battle. Kelsie took charge of the rebels, and continues to lead resistance operations today. She joins Yumi and the others.
Acquired Characters: Kelsie
Blossom's side of the team lands in The Park. Meanwhile, Mordecai and Rigby are more than ready for promotion day... but Benson has decided not to promote them! They start raking the yard until they find Blossom and co. lying there. Beau convinces them to join them on their mission, and they accept... but only because they want to be famous and get their promotion. With that being said, they enter a portal to Endsville.
Mandy is cleaning her room, because her half-brother (and sworn enemy) Marcus is spending the summer at her house. As Marcus comes in, he greets Mandy, Grim, and Billy before finding Blossom's group in the front yard. Blossom and Daffy debate over whether to let Mandy in on the mission, until finally they decide not to. Billy and Grim (and eventually, Nergal Jr.) agree to help them, but Mandy reveals a portal wristband and sends Marcus to a galaxy far, far away...
Acquired Characters: Mordecai, Rigby, Billy, Mandy, Grim, Nergal Jr.
Neo Thrownaway Mothership
Dexter and Tom are sitting in a prison cell, when they hear a spraying noise on the other side of the door. Batman shatters it, allowing them to escape. Some Thrownaway Soldiers and an unused design of Steven Universe's Lion attack them, but Batman and Tom manage to reach a portal to Gotham City. Bullet tries to lure Dexter into joining her army, but Julie Hinikawa drops in and saves him. She explains that the main reason she could move around in the Turner Portal was because she was a Thrownaway; thus, she managed to escape. She and Dexter enter a portal to Beach City, hoping they can find Peridot and the Crystal Gems.
Acquired Characters: TOM, Batman, Julie
Dexter and Julie knock on the Beach House door. Peridot of the prime timeline opens it, explaining that she was told to guard the house from intruders. Dexter describes the situation he's in and why he's on the run.
Robot units burst through the front door, and Dexter and Julie hide under the dining room table. Empress Peridot tries to convince Peridot Prime to join her, but fails; however, some of the robots find Dexter and Julie and proceed to capture them. Fortunately, Diva Dynamite (Dee Dee) saves them, and tells Dexter to twist the top knob on the watch Beau gave him. He does so, becoming Dek-Star. The two heroes fight the robot army, with the help of the Crystal Gems and the rest of their current allies.
Bullet, who was with Empress Peridot, feels a strange thing inside... the Force. She uses its power to the extreme and sends everyone through portals, including Empress Peridot.
Acquired Characters: Steven, Pearl, Garnet, Amethyst, Peridot
Peridot Prime wakes up in a strange, high-tech room... in space. Two robed figures enter, and she hides. The two figures remove their hoods, revealing Qui-Gon Jinn and Obi-Wan Kenobi. Through their dialogue, it is revealed that Peridot has crashed into the opening events of Star Wars: Episode I - The Phantom Menace. Obi-Wan points to Peridot, asking who she is, and the latter yelps with fear. Obi-Wan, seeing that she is currently powerless, gives her a lightsaber. Battle droids break in, and Peridot gets the gist of Jedi combat easily.
She grabs three space suits, one for herself and two for Qui-Gon and Obi-Wan. The three of them head through the portal Peridot had come out of.
Acquired Characters: Qui-Gon Jinn, Obi-Wan Kenobi
Bullet calls General Jones into the Peridotian throne room. The latter is confused, because it seems that he still has some humanity left in him. Bullet explains that this is exactly her point: he knows too much about Empress Peridot's true intentions. She commands some Mandark Units to force him out of the palace, and pulls up two holograms: one of Empress Peridot and one of a hooded figure. They exchange their plans for universal domination, and set their sights on another alternate future...
Kingdom of Dexterity
Dee Dee lands in a city, which is brightly lit and filled with technology. As she starts to wonder where she is, a person in advanced golden armor approaches her with a titanium sword. The person takes their helmet off, revealing an adult Buttercup (who calls herself Commander BC). She thinks Dee Dee is an "imposter", and arrests her.
An adult Dexter, the leader of this dimension, meets up with Commander BC and examines Dee Dee. He demands that she be locked up, but his wife -- Blossom -- calms him down. Queen Blossom tells Governor Onuki to guide Dee Dee into the mission room.
Dee Dee meets Dextrin and Dextrose, Dexter and Blossom's children in this universe, and becomes fond of them. Sergeant Rondeau, a future variation of Beau, recognizes Dee Dee, as Governor Onuki explains that she had sacrificed herself in the "past" to save Dexter from a villain known as Sedusa. Just then, a large warship approaches the mansion, while Dexter of the present rushes in. The ship tries to suck both Dexters up, but Dextrin pulls her father down. Dexter of the Present and Dee Dee are sucked into the tractor beam.
Dexter and Dee Dee are taken to a chamber where Empress Peridot, Bullet, and the hooded figure hook them to machines. The hooded figure reveals herself as Sedusa, and states that she needs some of their "life force" to create new commanders for her interdimensional army. Bullet brings in Robots Taylor, Tyler, and Shawn to pull the switches, and as a result, semi-clones of Dexter and Dee Dee are created.
The clones, dubbed Sagaci and Loo Loo, have personalities that combine Dexter's intelligence with Dee Dee's trustworthiness. Dexter and Dee Dee themselves are sent through a portal back to Huber, where they will find something unexpected...
Acquired Characters: Dextrin, Dextrose.
Dexter and Dee Dee find their town in flames. They look around for any survivors, but they see a pair of giant insect-like legs crash in front of them.
A giant praying mantis is standing there, waiting to strike. Mandy steps up behind Dexter and announces that she has found this monster... somewhere, but she won't say where. She tells her "pet" praying mantis -- named Gerald -- to chase Dexter and Dee Dee away. They seek shelter in Dexter's lab.
Inside the lab, Dee Dee points out an old, dusty robot that looks kind of like Robot Jones. Dexter decides to repair it, believing it will still work. Robot 1.0 becomes fully functional, and curiously looks around. Then, as if the mantis wasn't enough, two more monsters show up: a werewolf and the Abominable Snowman.
Mandy arrives, and Robot 1.0 rushes to his so-called "mistress". Dexter is confused, and Mandy tells him that she tried to take control of a robot army and rule the world, but the CIA stepped in and stopped her. They reprogrammed the robots for the good of international justice. However, Mandy knows that Dexter found a blueprint for the robots, which is how Robot 1.0 came into existence.
As for the monsters, she states that she didn't create them -- she summoned them. With that, she commands the werewolf and Abominable Snowman to get rid of Dexter and Dee Dee. They fight the monsters, with the Powerpuff Girls soon arriving and joining in.
Acquired Characters: Robot 1.0.
Beau and Julie end up in a strange place filled with computerized images. Beau looks through his dimensional database and says that they are in Backspace, a place where every bad idea in the Tooniverse goes. He notices a cab on rails pulling up to them, with a girl in the driver's seat. As Beau and Julie sit down, she welcomes them to Backspace, introduces herself as Patti, and says that they are under arrest.
Beau and Julie are brought into a large Thrownaway base, where they are taken to the front office. There, they meet the Thrownaway Legion Director, Lalavava Astromonomov. She decides to punish Beau and Julie separately; Julie will be shredded and fed to sharks, and Beau will be imprisoned in a binary chamber, where he will be forgotten forever.
As a group of Thrownaway Soldiers guide Beau to the chamber, he teleports behind them using his portal device, punches them in their heads, and runs to save Julie. After he succeeds in stopping the execution, the two of them escape through a garbage chute -- and land in front of a legion of Thrownaways. Lalavava commands them to eliminate the rebels, who must escape. They soon come across the Reality Runners -- Darius "Ridge" de Gucho, his sister Kaitlyn a.k.a. Rush, and their best friend Philip "Dust" Odell. They board a rail cab, with Patti in tow. The latter explains that she's tired of working with the Thrownaways, who took over Backspace a while back. She says she needs to figure out who she really is, and believes Beau and Julie can help her. The six heroes board the Reality Runners' spacecraft, which boosts out of Backspace.
Acquired Characters: Ridge, Rush, Dust, Patti.
Brick leaps into an alley with Ace. He inputs a code, and a hidden door opens. The two of them search for anything they might want to take back to their hideout. Suddenly, a horde of robot body parts attacks them. Ace is surrounded, but Brick escapes.
In a fight club, Butch takes on Man-Boy and some of his goons. Brick charges in just as Butch is getting ready to knock out Man-Boy. Butch asks him why he left him, and pounds him into a dance club, where Boomer is mixing up some beats. Brick and Butch have a battle, catching the audience's attention.
Brick, Boomer, and Butch -- the Rowdyruff Boys -- have been split up for a long time, but they must reunite to fend off the robot portions. Some parts push Butch into a strange machine, where he is covered with a black liquid...
Butch wakes up, and realizes that his body is almost half-covered with robotic parts.
Acquired Characters: Brick, Boomer, Butch.
Ami, Yumi, and the Crystal Gems come across Tokyo. They head for the Yoshimura residence to find Yumi's father Ronu, who works for the CIA.
Ronu grants Yumi permission to borrow his dimension hopper, but he states that she will be grounded for a month if she brings it back broken. As Puffy AmiYumi and the Crystal Gems gear up, Ami and Yumi's half-sister Kiki sneaks onto the shuttle.
Acquired Characters: Kiki.
Dexter, Dee Dee, Robot 1.0, and the Powerpuff Girls begin to decide what to do about the monster situation. Buttercup thinks they might have come from a mysterious dimension isolated from the Tooniverse.
Some CIA agents arrive to pick up Robot 1.0, whom they see as a "threat" to the safety of the town. Blossom pushes him over to them, and reveals that she isn't the real Blossom. Robot 1.0 refuses to go with them, so "Blossom" smashes his light bulb and leaves with the agents.
The true Blossom is stuck under the debris from the destruction the monsters caused. She crawls out, saying that she doesn't feel too well. Then, Dee Dee points out that there is something... different about Blossom's outlines. Buttercup grows a tuft, Bubbles suddenly has beads in her hair, and all three of their voices have changed. Dexter realizes that a strange energy from the monsters is mutating them, so they set out to the Mystic Realmto find a cure.
Sedusa peers out the window of her warship's main deck, examining interdimensional space. Some Mandark Units bring in her new prisoners -- King Dexter and Queen Blossom. When asked where their children are, Sedusa explains that she has banished them to the parents' past, hoping to cause a paradox. She and Empress Peridot have also formed an alliance with a mysterious businessman who is using Chemical X to create soldiers just like the Powerpuff Girls. These troops will form a false sense of security throughout the universe, but will actually be serving Sedusa when she takes Oceanbird's place as the ruler of the universe.
As the king and queen are pushed out, Sedusa peers at a picture of Oceanbird. "I'm coming home," she says as if she was really talking to her, "whether you like it or not."
Gumball and Robot Jones walk around the city they've landed in, and see a swarm of aliens soaring around. They see a green gorilla being thrown out the window, as a strange robot-like man fires lasers from his arm cannon. A dark girl flies towards an alien, pushing it backwards with dark energy blasts. Someone a comlink tells the "gorilla" -- Beast Boy -- to watch out for the other aliens, and he punches them away.
After beating the last of them, Raven finds Gumball and Robot hiding in a dumpster. She, Beast Boy, Cyborg, Starfire, and the leader -- Robin -- question their motives at first, but when they realize that they are from alternate dimensions, they decide to help them out.
Bullet barges into the Teen Titans' T-Tower, hoping to get Raven on her side. She tries to brainwash her, but attacks from the other heroes distract her, eventually transforming Raven into a self-obsessed "goddess". Raven fights both sides, and leaves because she thinks they are too incompetent.
Bullet blames Robot for what happened to Raven, and is so angry that she snaps his arm off. Robot is upset, and asks her what Bubbles would think of what she did. He leaves, telling Bullet not to request his help when everything she loves is destroyed. Bullet begins to show sadness, but covers it up.
Robin asks Gumball if he knows any other people from other dimensions, and the latter states he's heard of a creepy scientist who is almost exactly like Dexter...
In a cutscene, Oceanbird arrives in Huber and tells Mandark and the Rowdyruff Boys that Sedusa is her sister. The two ruled the multiverse together as they promoted safety all across its realms. However, Sedusa betrayed her and set out to wreak havoc, believing that the world wasn't wild enough. Oceanbird punished her by permanently distorting her hair, stripping her of her celestial status, and banishing her to the mortal world. Fearing that Sedusa may be seeking revenge on her, she tells the boys to head out and find the others.
Acquired Characters: Robin, Cyborg, Starfire, Beast Boy.
The Mystic Realm
Dexter, Dee Dee, and the Powerpuff Girls search through the Mystic Realm for a cure to the girls' strange moprhing sequences. Eventually, the dimensional disturbance becomes so bad that the thin outlines pop off the PPG, who are restored to their normal selves. The outlines assemble in front of them, forming alternate versions of Blossom, Bubbles, and Buttercup.
The 1998 and 2016 girls argue for some time, but they have to fight a chimera that is roaming around. After defeating it, Dexter guides them to Polyneux.
Acquired Characters: New Blossom, New Bubbles, New Buttercup.
The Legacy Squad meets up in the town, where they try to choose their next move. They come across with Lenny and Denny Yogman, who decide to work with them after realizing that most of the students at Polyneux Middle School have vanished.
Dexter, Robot Jones, and Blossom look around for any survivors, and run into Mandark and the Rowdyruff Boys. After arguing for a while, they form a truce and continue searching.
The squad arrives at the middle school, which is in flames. Based on the evidence, they come to the conclusion that the enemy is using a sort of weapon to trap citizens of all dimensions in Backspace. Suddenly, five secret agents in blue uniforms crash through a wall, coming face to face with the Legacy Squad. Hoss Delgado, Irwin, General Skarr, Jeff the Spider, and Fred Fredburger -- together known as Underfist -- grab Dexter and force a sort of energy into his body, causing him to grovel with agony, as a group of Mandark Units hold his friends back. As the energy is about to finish consuming him, Peridot charges in and swings a metal rod at Hoss, causing him to let go of the energy staff. TOM, Batman, Obi-Wan Kenobi, and Qui-Gon Jinn arrive with her, and help the other heroes fight Underfist. Dexter finds an emerald embedded in the palm of his hand, and realizes that he is now able to toss energy spheres at enemies, as well as summon holographic wrist blades.
Each player is able to choose any character they have unlocked so far to fight Underfist. After the battle, they retreat back to Sedusa's warship.
Acquired Characters: Yogman Twins.