Ben 10: Ultimate Ali
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").
Five years prior to the start of the series, a massive explosion released nanites into the atmosphere, infecting every living thing on Earth. These nanites randomly activate inside their hosts, mutating the subject into a monster known as an E.V.O. (Exponentially Variegated Organism). These Evos are usually mindless creatures that are a danger to everything around them. To combat the Evo threat, the organization known as Providence was created to capture and cure them.Rex is a 15-year-old amnesiac teenager who, like everyone else, has been infected with nanites. However, unlike most Evos, Rex can control his nanites, allowing him to manifest a variety of powers and even cure other Evos of their mutations. Working with Providence under Agent Six, he helps stop the Evos as they appear. Working against Providence is Van Kleiss, an Evo with connections that are not only to the event which released the nanites, but to Rex as well.
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.