The story of Ben, a typical kid who becomes very atypical after he discovers the Omnitrix, a mysterious alien weapon with the power to transform the wearer into ten different alien species.
After a battle in a power plant, Ben notices something strange is happening with the omnitrix, but doesn't tell anyone. Tetrax arrives, and tells them the omnitrix is broadcasting a self destruct signal. Tetrax and Ben go to find the creator of the omnitrix to fix the omnitrix before it destroys itself and the universe along with it. Gwen stows away to help her cousin.
Ben, Gwen, and Max must stop an extraterrestrial who plans to open a gateway that leads to an alien invasion.
Ben 10: Alien Force is the sequel to the hit Cartoon Network series, Ben 10. The series takes place five years later after the original. Ben no longer wears the Omnitrix, and his cousin, Gwen, has honed her skills in magic. But when an alien invasion of the DNALIENS strike Earth and Grandpa Max goes missing, Ben decides that it's hero time once again. He's not alone, as he is joined by Gwen, and even his old archenemy, Kevin Levin comes along for the ride. Now it's time once again for Ben to begin his quest to find his grandfather and stop the invasion from the evil DNALIENS.
Against his grandfather's orders, Ben Tennyson teams up with the daughter of an old enemy in order to prevent an alien infestation of earth.
Taking place a few weeks after where Ben 10: Alien Force leaves off, Ben 10: Ultimate Alien follows the now sixteen-year-old Ben. The Omnitrix has been destroyed and Ben must learn to master the secrets of the new Ultimatrix, a gauntlet-like version of the old Omnitrix that not only gives him access to all of his original powers and abilities, but also allows him to evolve his alien forms into even stronger and even more powerful versions (called "ultimate forms").
Four fans are sent to Ben's secret base to learn the secrets of the Omnitriks and fight with the villain Ilgaksom. Participants compete in question rounds and perform tasks of skill and ingenuity.
A mysterious rift begins to open in the skies of Manhattan. Meanwhile, former agent of peacekeeping organization, "''Providence''", Rex Salazar is sparring against fellow agent, Agent Six, while musing about his need for a theme song, before getting the alert about the rift. Providence appears on the scene to stop the rift, but are unable to do anything before Rex arrives with Six and Bobo. Doctor Holiday, scientist and love interest of Agent Six, then gets a scan that shows something is coming through the rift, and Rex finds himself (unknowingly) fighting against Ben Tennyson, in the form of Humungousaur. During their skirmish, a strange metallic creature also appears and heads into the city, with Bobo and Six on its trail. Continuting their fight across New York, Ben switches to Diamondhead, Lodestar and finally Rath as Rex continues to try curing him; an annoyed Ben demands Rex stop as he doesn't even know what an EVO is. Changing back to human form, Ben is shocked that no one has heard of him despite being a celebrity. Then, Six appears with the creature, which self-destructs and renders him comatose, leaving Rex mortified and angered at Ben.
Ben Tennyson, his cousin Gwen and his Grandpa Max spend their evenings fighting aliens on the streets of Bellwood. During a battle against a robotic tank, Ben as Upgrade and Gwen argue about the best way to defeat it, leading to Gwen using her extraordinarily strong Pink (color)-colored Magic (paranormal) to cast a dismantling spell on the tank while Ben is attached to it. Unknown to the children, this leads to a strange malfunction in the Omnitrix.
Ben 10: Omniverse features Ben who is all set to be a solo hero, but Grandpa Max teams him up with a rookie, by-the-book partner. Together they explore a secret alien city. Meanwhile, a mysterious hunter sets his sights on Ben! With ten new alien heroes to choose from, the fun is just getting started. It's a whole new Omniverse!
Ben Tennyson, his cousin Gwen, and Grandpa Max travel the country for summer vacation. When Ben finds the Omnitrix, a mysterious watch that transforms him into 10 different aliens, a world of extraterrestrial superpowers opens up before him.
When a giant meteorite crashes towards Earth, Ben immediately flies into space to prevent the planet from being destroyed. However, the alleged meteorite is actually a spacecraft piloted by Vilgax, who is heading towards Earth unchecked and with bad intentions. With Ben stranded in the depths in space, the rest of Team Tennyson must team up with Kevin, who has to step up to help protect the world in Ben's absence.
After years of saving the universe, an older Ben Tennyson find hinself in danger when the Omnitrix begins behaving abnormally.