Ben10 Alien Force is an American animated television series produced by the Cartoon Network. It is a sequel to Ben 10 set five years after the original series. The storyline is notable for having matured the character and taking a darker tone, with more complex plots.

The series premiered on Cartoon Network on April 18, 2008 in the United States, with its Canadian premiere on Teletoon on September 6, 2008. The series was originally produced under the working title of Ben 10: Hero Generation and has spun off a series of Ben10 Toys.

Five years after the events of the original series, 15-year old Ben Tennyson has returned to a normal, everyday life. His adventures done, Ben has taken off the Omnitrix and has grown from a young boy into a confident teenager. But the mysterious disappearance of Grandpa Max prompts him to wear the omnitrix then Ben, Gwen, and a newly reformed Kevin Levin to search and locate him. While at the same time enlisting the help of child Plumbers and repelling attacks from a new foe DNAliens and The Highbreed.

Some time after the Highbreed are defeated, Ben, Gwen, and Kevin continue their adventures dealing with various alien threats. These include facing off with some villains from Ben’s past such as Vilgax and Vulkanus.

Ben10 Heroes

Benjamin Tennyson
Ben fills the role of leader after Max disappears. The Omnitrix has been recalibrated, giving him access to a new set of alien heroes. Over the past few years, Ben has matured dramatically.

Gwendolyn Tennyson
Gwen is much more proficient with her powers, able to manipulate energy directly as opposed to using spells (this is revealed to be due to Gwen having an alien heritage), where she can manipulate energy to create blasts, shields, and energy like grapple holds. Although she’s not nearly as fiery or short-tempered as before, Gwen is still always looking out for her cousin. She also is presumed to have feelings for Kevin Levin.

Kevin Ethan Levin
A former nemesis of Ben, Kevin is now getting by as an alien tech dealer. He unintentionally gets involved in the Highbreed plot, and joins Ben out of a desire to make up for his actions. His abilities now allow him to absorb the properties of any solid matter he touches. But in the third season premiere Kevin is mutated into a being with a segmented body composed of several different solid substances, and as a result, he now has the power to shape-shift his limbs into any solid substance he can think of. He is also presumed to have feelings for Gwen Tennyson

Max Tennyson
Max is a semi-retired member of the Plumbers. He disappears while investigating the Highbreed plot, leaving only a few cryptic messages for Ben to find. He is briefly reunited with his grandchildren in “Max Out”, but sacrifices himself to destroy a Highbreed factory at the end of the episode. In the episode “Voided”, Ben and Max reunite in the Null Void, and he promises Ben that he’ll come back soon. He eventually returns in the second season finale of the show, “War of the Worlds” to aid Ben in his final assault against the Highbreed.

Julie Yamamoto
Julie is Ben’s girlfriend. She enjoys tennis, eating chili fries, and caring for her pet, Ship (an alien Mechomorph found by her and Ben).

Ben10 Villains

Highbreed
The Highbreed believe themselves to be the purest of all species, and intend to cleanse the galaxy of impure lower life forms. Earth is their current target. It is later revealed that they are dying out, having lost their resistance to disease due to heavy inbreeding, and that they intend to destroy the rest of the universe with them.

DNAliens
Hybrids of humans and alien drones that serve the Highbreed, the DNAliens are able to disguise themselves as humans using special identity masks.

The Forever Knights
An organization that has worked in secret ever since their formation in the Middle Ages. The Forever Knights will trade alien technology with anyone who’s willing, even the Highbreed.

Vilgax
Vilgax returns in Season 3 with a new look (he had new armors, weapons and abilities). He loses to Ben in the episode “Vengence of Vilgax” and was banned from Earth, though he swore vengeance.