Taking place a few weeks after where Ben 10: Alien Force leaves off, Ben 10: Ultimate Alien follows now 16 year old Ben. Based on the original series is also a movie called Ben 10: Destroy All Aliens. Ben’s secret identity has been revealed to the world and he is now an international mega-star superhero. 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 – ultimate forms. The second season features more self-contained stories rather than employing an overall storyline, although a real storyline is developing with the appearance of the mysterious but dangerous Old George and the extradimensional demon Lucubra. This series will be succeeded by Ben 10: Omniverse.
Ben turns into Ultimate WayBig to fight Diagon but fails to win. Eventually, Diagon destroys George but Vilgax betrays and absorbs all the powers of Diagon. Apparently, Ben retrieves George’s sword and defeats Vilgax. In the end, Azmuth appears and gives Ben the newly customized Omnitrix.
Ben, Gwen, Kevin, and George trash Diagon’s City while battling a reborn Lucubra-morphed, power hungry Vilgax.
Sir George battles the Flame Keepers’ Circle and Vilgax.
Ben fights his way through old enemies only to confront Anodite Gwen and Ultimate Kevin, who attempt to take the Ultimatrix from him.
Ben and the gang have to stop Dr. Animo. Jury Rigg will make his debut.