This article is a stub. You can help Ben 10 Planet by editing it.
After the events of Ultimate Alien, Ben is left to be a sole hero after Gwen and Kevin leave for college. However, Grandpa Max has other plans. He teams Ben up with a Plumber rookie just out of training, Rook Blonko. Ben does not want to have a partner and tries refusing Rook, but in vain. Setting their differences aside, the two soon learn to work as a team and look out for each other.
11 years old Ben: Ben as Four Arms fought Malware. While at first it appeared that Ben was winning, Malware managed to grab the Omnitrix and forced Ben to revert back to human.
Malware confronted Ben and taunted him about his defeat, which allowed just enough time for the Omnitrix to activate again. Ben transformed into Feedback and used his energy absorbing and redirecting powers to quickly defeat Malware.
Ben and Rook check out a mysterious ghost ship. Later on after meeting old enemies, Ben has to use Alien X to save the universe from a raging bomb. When Ben transformed back from Alien X, he gained a green and white jacket that had a hoodie, and a number 10 logo on it.
16 year old Ben: Ben is attacked by Khyber and his pet. He turns into Crashhopper to battle, but Khyber's pet turns into Mucilator and falls on Crashhopper, so Ben turns into Armodrillo and throws Mucilator.
Mucilator later turns into Slamworm and goes underground, attacking Armodrillo. Armodrillo turns into Heatblast and chases after Khyber, but meets a surprise attack by Crabdozer. Heatblast tries to turn into Humungousaur, but becomes a new alien named Ball Weevil. At first Ben didn't know how to use Ball Weevil's powers, but then spits a ball and rolls around uncontrollably before seeing that the ball can explode. Crabdozer counters this by turning into Terroranchula.
Ball Weevil flees, but Khyber defeats him by redirecting one of his balls. Ball Weevil reverts back into Ben and falls down unconscious.