He has advanced combat knowledge and wields the multi-purpose Proto-Tool. Rook Blonko is a Revonnahgander Plumber from the planet Revonnah, who serves as Ben's partner throughout Omniverse after Gwen and Kevin leave the team. However, he later reformed and is now his friend and Gwen's love interest. Kevin Ethan Levin is an Osmosian, a mutant subspecies of human, who first appeared as one of Ben's enemies.
Maxwell ' Max' Tennyson is a retired Plumber and the paternal grandfather of Ben and Gwen. Jason Marsden – Ben 10: Ultimate Alien (as a young adult in 'Moonstruck').Adam Wylie – Ben 10 (as a kid in 'Don't Drink the Water').Paul Eiding – Ben 10, Ben 10: Alien Force, Ben 10: Ultimate Alien, and Ben 10: Omniverse.Gwendolyn ' Gwen' Tennyson is Ben's paternal cousin and Kevin's love interest, a skilled sorceress who inherited her magical 'spark' from her Anodite grandmother, Verdona. Galadriel Stineman – Ben 10: Alien Swarm.
