Ben 10 - Generator Rex: Destroyer of Worlds

In this sequel to Ben 10/Generator Rex: Heroes United, in Rex's Universe,                                                           a new threat has risen. As Rex battles an Evo, an accident releases a portal to Ben's Universe and even worse... the Prision of the Destroyer, Graon. Graon is the Destroyer of Worlds. As Graon attacks Generator Rex's universe, and no one ... even Rex can stop it, he calls on his only friend from the other universe, Ben 10 himself. It will take all of his Xobots, Aliens, and his allies to stop Graon and his minion of Evos and Aliens to save two universes.

Trivia

 * This takes place between Season 2 and Season 3 of Ben 10 Xobot Revolution.