The StoryEditAlien Force is 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 and more characters dying. This change received mixed reactions from the fans, and caused a division amongst them. Despite this, Alien Force's ratings were successful, allowing the production of Ultimate Alien.
At the beinning of "Ben 10: Alien Force" the Omnitrix recallibrates and leaves Ben with 10 new alien forms. Like in the past series. Swampfire, Echo Echo, Humungousaur, Jetray, Big Chill, Chromastone, Brainstorm, Spidermonkey, Goop, and Alien X .
Lodestar, Nanomech and Rath.