Ben 10: Omniverse Season 1 Episode 21 Showdown Part I

In Ben 10: Omniverse season 1 episode 21, titled Showdown Part I, Ben and Rook are on a mission to stop the evil Khyber from obtaining a powerful weapon. Khyber and his pet, Zed, have been hunting down Ben's alien forms, including the highly sought-after predator alien, which could be the key to unlocking the weapon's potential.

Meanwhile, Ben's old nemesis, Vilgax, has returned and is seeking revenge on Ben. He enlists the help of Psyphon and Sevenseven, two of Ben's other foes, to capture Ben and lure him into a trap. However, Vilgax's true intentions remain shrouded in mystery.

The episode sees Ben and Rook battling against Khyber and Zed in an intense showdown, which results in Ben losing access to his most powerful alien form. As they continue on their mission, Ben and Rook encounter a group of bounty hunters, each with their own unique alien abilities. The duo must navigate their way through the treacherous gang and try to stay one step ahead of Khyber and his pet.

Meanwhile, Vilgax's plan begins to unfold, as his henchmen capture Ben and bring him to his lair. With the help of a mysterious entity, Vilgax is planning an ultimate showdown with Ben, and Ben must use all of his skills and abilities to stay alive and defeat his foes.

As the episode comes to a close, Ben and Rook are left trapped and alone, facing their greatest opponents yet. With Khyber on their trail and Vilgax's sinister plan in motion, the fate of the universe hangs in the balance. Can Ben and Rook overcome their enemies and save the day, or will they be defeated in the ultimate showdown? Find out in Ben 10: Omniverse season 1 episode 21, Showdown Part I.