Ben 10/Generator Rex Heroes United Episode Title:Generator Rex Heroes United.Episode Description:A mysterious rift begins to open in the skies of Manhattan. Meanwhile, former Agent of peacekeeping organization, "Providence", Rex Salazar is sparring against, fellow agent, Agent Six. While musing about his need for a "Theme song" (and briefly performing a take on the original Ben 10 theme song) before getting the alert about the rift. Providence appears on the scene to stop the rift, but are unable to do anything before Rex arrives with Six and Bobo. Holiday then gets a scan that shows something is coming through the rift, and Rex finds himself (unknowingly) battling all-star superhero, Ben Tennyson, transforming into multiple aliens, such as Humongousaur...