Ben 10: Ultimate Alien (2010) follows Ben Tennyson as he masters the powerful Ultimatrix and unlocks incredible Ultimate alien transformations. Joined by Gwen and Kevin, Ben battles dangerous villains, alien threats, and powerful enemies in this action-packed Cartoon Network animated series filled with sci-fi adventure, superheroes, comedy, friendship, and unforgettable alien transformations.
Ben's secret is out. As Ben deals with his newfound fame, a new threat emerges as a thief steals parts of a new advanced spaceship from NASA.
Ben is supposed to attend a tournament to support his girlfriend, but the Forever Knights are trying to break into a museum. Ben tries to use the Ultimatrix to handle all his obligations.
With Ben's identity known, some of his enemies (such as Zombozo, Rojo, Charmcaster, Vulkanus, and SevenSeven) team up to try to attack his family. Now Ben and friends have to protect them no matter what.
Ben gets an offer to star in his own video game, but the designer's real motives are part of a plan to destroy Ben.
The team encounters another alien who escaped from Aggregor and, through him, learns more about Aggregor's goals.
P'Andor, escaped from Aggregor, now wants help to escape his encapsulating suit, but Kevin's the first to perceive that that's a fatally bad idea.
Then team encounters another of Aggregor's escaped prisoners, Andreas, whom Argit is using as part of a scheme against the Forever Knights.
Ra'ad, the last of Aggregor's escaped prisoners, attacks Ben and informs the team of the true fate of his comrades. He finds a safe hiding place but one that endangers Ben in the process.
Ben meets his hero, Captain Nemesis, who's become jealous of all the attention Ben attracts.
Aggregor has all five aliens. The Plumbers manage to disable Aggregor's ship, forcing Aggregor to find a new way to absorb their powers. The team makes a last ditch effort to save the alien prisoners.
Aggregor has absorbed all the powers of his captured aliens. Now he's after the Map of Infinity.
Cash and JT convince the team to allow them to take credit for the team's actions so they can earn money for Cash's mother's operation.
Aggregor is after the next piece of the map on a watery planet.
Aggregor escapes to a magical dimension. Gwen asks for Charmcaster's help to pursue him. The team learns about Charmcaster's past and why she's willing to help them now.
The last piece of the map is hidden in an artificial puzzle world.
As the team makes its final attempt to stop Aggregor, they find an unexpected ally, and one person will make a fateful decision with lasting repercussions.