Ben 10: Alien Force
Ben, Gwen, Kevin, and Labrid defeat the robotic dragon and the Forever Knights, but in the process, Labrid is critically wounded. Telling Ben to keep investigating the alien conspiracy and to believe in himself, Labrid dies. Kevin, taking Labrid’s Plumber’s badge, agrees to continue helping Ben and Gwen. They trace the aliens to a huge underground facility housing a massive spaceship. Gwen concludes that Max was previously in the facility, but left. Ben decides that they need to finish the mission, and they proceed deeper into the facility, where they encounter an army of aliens led by an enormous, virtually invulnerable Highbreed. Ben duels the Highbreed until their spaceship launches, and the Highbreed orders the destruction of the surrounding area to hide their activities. Ben is able to sabotage the ship just before it vaporizes a hospital, and it crashes and explodes in the desert. Ben, Gwen, with Kevin now alongside them, then decide to continue working together to find out what happened their paternal grandfather.