Cartoon All-Stars Cosmic Clash is a new movie and it's a sequel to Cartoon All-Stars Unite,Cartoon All-Stars Battle for Volcano Island,Cartoon All-Stars Attack of the ToyBots and Cartoon All-Stars Globs of Doom. It is a crossover of My Little Pony Friendship is Magic,DC Super Hero Girls,Transformers Robots in Disguise (2015),Bionicle,The Mask Animated Series,Yo-Kai Watch,Ninjago Masters of Spinjitzu and Power Rangers Time Force.
After the events of Cartoon All-Stars Globs of Doom Brainiac have come to Earth to control the Earth to add it to his planet collection so it's up to the Cartoon Veterans to stop him.
After bottling planet Earavixlu, Brainiac accidentally drops the planet destroying it. In order for his collection of planets to be complete, Brainiac decides to go after Earth, a planet Darkseid mentioned in his suggestion box.
Back on Earth, Twilight Sparkle witnesses Ronin and Von Ness apprehend Xplode and Samukai. Twilight Sparkle begins to enjoy being part of the Cartoon Veterans, reminiscing on how she refused to join just years ago. When returning to the Hall of Cartoon, Twilight is disappointed as to how the rest of the Cartoon Veterans was playing hide and seek. The Cartoon Veterans then say that Twilight needs to learn to spend fun times with friends. However, their life lesson is cut short when Brainiac's spaceship is detected.
After encountering the Cartoon Veterans, Brainiac studies them and their powers. Due to Twilight's lack of superpowers, Brainiac does not consider him a threat. Following the Cartoon Veterans defeating him (and jokingly applying a moustache to his spaceship), Brainiac retreats to the Brainiac Hive for repairs along with a smaller spaceship to use until the one he uses to shrink planets is repaired. During this time, two duplicates of Brainiac (referred to as Brainiac 1.2 and Brainiac 1.3) grow jealous of the original Brainiac (or Brainiac 1.1 as he is known as to the Hive) and devise a plan to exterminate him.
Returning to Earth, Brainiac once again draws the attention of the Cartoon Veterans. This time, only The Mask, Preston Stormer and Supergirl attempt to stop him. Brainiac uses a weapon that instantly causes them to seemingly vanish into thin air. Twilight deduces that the weapon did not destroy them, but rather scattered them across time. Identifying the years their fellow Cartoon Veterans were sent to, Twilight Sparkle and the rest of the Cartoon Veterans use a secret tunnel to head to the Crystal Empire to make upgrades to Starswirl the Bearded's time spell, turning it into the Cosmic treadmill. Twilight and the Time Force Rangers use the Cosmic treadmill to travel through time to find their fellow Cartoon Veterans starting with Supergirl while the rest of the Cartoon Veterans calls upon the first Nate Adams, Whisper and Jibanyan to help him hold off Brainiac's forces as she was the only one available at the time.
In the Stone Age, Twilight Sparkle creates a detective disguise to search for Supergirl while the Time Force Rangers stays behind to keep running on the treadmill (to prevent it from going back to the present and trapping them and Twilight in the past). Twilight finds Eclipso (who has not yet experienced her origin) holding a girl named Principal Waller hostage. Twilight frees Principal Waller, but to her surprise, she and Eclipso end up captured by Principal Waller and taken to her tribe of supers to be roasted in a pit of lava. In their cave, Twilight and Eclipso are introduced to the queen of the tribe: Supergirl (whose memories were warped to stabilize the time stream) who gained her position by freeing the tribe from Eclipso and her shadow warriors. Twilight manages to free himself and Eclipso from the restraints and uses the kryptonite to restore Supergirl's memories. With her memories retained, Supergirl is sent back to the present to stabilize the time stream, but not before she promotes Principal Waller as the new queen. As Twilight leaves the cave, she hears Principal Waller talking about plans to leave to an city in the building with the Amethyst of all villains that will be their "Super Hero" explaining to Twilight how Super Hero High came to be. Back in the present, Supergirl arrives to assist the Cartoon Veterans.
As the Time Force Rangers and Twilight use the Cosmic treadmill to travel to the 1600s to find The Mask, the Time Force Rangers begins to tire. Twilight gives them a soda to keep him going. Twilight manages to find the Mask on a pirate ship run by a pirate named Captain Fear where he had become a cowardly deck swabber named Swabbie. Twilight (disguised as a fellow pirate) takes the Mask to confide his disguise to him and tries to use the Mask's mask to restore his memories, but is witnessed by Captain Fear who took the mask as treasure. As Twilight is forced to walk the plank, she tells the Mask to use the mask and remember the funniest man he truly is. The Mask uses the mask and regains his courage and memories, using the mask to destroy Captain Fear's ship. To the misfortune of the crew, a school of sharks begin to chase after them. The Mask is sent back to the present as the Time Force Rangers and Twilight travel to the future.
When Twilight and the Time Force Rangers arrive in the future, the cosmic treadmill is damaged sending the Time Force Rangers and its remains back to the present. In this future, Brainiac has taken over the planet and turned Preston Stormer into an obedient cyborg henchman. Luckily, Twilight is saved by the Resistance of this timeline, Cosmic Boy, Lightning Lad, and Saturn Girl, the last surviving members of the Legion of Super-Heroes. The Legion of Super Heroes attempt to hold off Preston Stormer, but they are killed. Twilight manages to get to the Crystal Empire to find a weapon he needs to defeat Stormer. Surprisingly, Twilight does not use a bomb, but rather a weapon which shoots Quaza energy. Although the weapon enhances Stormer's powers, it fries his cybernetics including Brainiac's control over him. Twilight states he did this to free Stormer without harming him. Back to his normal self, Stormer returns to the present.
In the present, Brainiac summons dinosaurs from the past to combat the Cartoon Veterans. Finally, Brainiacs 1.2 and 1.3 arrive with a new shrink ray that can link with Brainiac's eye beams. Knowing it is a trap, Brainiac 1.1 kills Brainiacs 1.2 and 1.3 and disables the trap. Brainiac then uses the new shrink ray to miniaturize the Earth. At this moment, Twilight uses the last Legion Time Bubble to return to the present as the death of the Legion was an illusion cast by Saturn Girl. Zane reveals how they can stop Brainiac. Zane reveals to have built six aerial vehicles for the Cartoon Veterans. They use these vehicles to escape the bottle and combine them to form a robotic mech. Twilight sneaks into Brainiac's head and puts the shrink ray into reverse causing Earth, the Cartoon Veterans, herself and the mech to return to their normal sizes.
Feeling he may never complete his collection, Brainiac sets himself to self-destruct. In order to avoid the blast radius, Twilight convinces Brainiac to collect coins instead of planets. Brainiac is then put in prison. Now having learned the value of her friends, Twilight and the Cartoon Veterans celebrate their victory by playing hide and seek.
This film is based on LEGO DC Comics Super Heroes Justice League Cosmic Clash