For years, rumors circulated about a follow-up movie titled Heroes United 2, which would have featured Ben, Rex, and possibly Zak Saturday (from The Secret Saturdays) uniting against a multiversal threat. Artifacts from Man of Action’s concept boards leaked in 2018, showing a design for “Ultimate Upgrade Rex.” However, with Generator Rex ending and Ben 10 rebooting in 2016, the sequel remains a holy grail of lost animation projects.
Upon arrival, Ben’s Omnitrix malfunctions. He is immediately attacked by EVOs (Exposed Vitrue Organisms—mutated animals and humans). Confused and on the defensive, Ben transforms into four different aliens (Humungousaur, Echo Echo, Rath, and Big Chill) in quick succession, trying to regain control. ben 10 generator rex heroes united movie
Enter Rex Salazar. Rex patrols the ruins, using his "Builds" (massive machines sprouting from his body) to contain EVOs. He spots Ben (as Humungousaur) and mistakes him for a massive, rampaging EVO. The two titans clash in a spectacular, debris-filled brawl that defines the first act. For years, rumors circulated about a follow-up movie
Unlike many crossovers that are brushed under the rug, Heroes United is repeatedly referenced. In Generator Rex’s Season 3 finale, Rex directly mentions “that kid with the watch who helped me fight a crazy nanite.” In Ben 10: Omniverse, Ben briefly recalls fighting a “techno-kid from another dimension.” This continuity respect gives the movie weight. He is immediately attacked by EVOs (Exposed Vitrue
Furthermore, the film introduces the concept of inter-dimensional travel between the Ben 10 universe and the Generator Rex universe. Man of Action has since hinted that the two worlds exist on a shared multiverse, leaving the door open for future crossovers (which, sadly, never happened due to Generator Rex’s cancellation in 2013).