Episodes: 51–60 Focuses on the "Galactic Monsters" arc, introducing new horror-themed aliens.
This arc re-examines the lore of the Osmosians and the Kevin Levin backstory through the lens of the shadowy Plumber black-ops group, The Rooters. Collect This The Rooters of All Evil Blukic and Driba Go to Area 51 No Honor Among Bros And Then There Were None And Then There Was Ben The Vengeance of Vilgax Cough It Up The Color of Monkey Arc 7: The Mad Ben World ben 10 omniverse ep list
Here is the list of Ben 10: Omniverse episodes in text format: Episodes: 51–60 Focuses on the "Galactic Monsters" arc,
Episodes: 71–80 The final season wraps up the Time War and the series. And Then There Was Ben – No Watch
41. And Then There Were None – Vilgax gathers evil alternate Bens to destroy the prime Ben. 42. And Then There Was Ben – No Watch Ben (a Ben without an Omnitrix) must save the multiverse. 43. Cough It Up – Argit and Psyphon fight over "treasure." 44. The Vengers – A superhero team forms in Bellwood to upstage Ben. 45. Cats 'n' Mice – A classic Tom & Jerry style chase with a twist. 46. Bengeance is Mine – A plumber named Bill Gacks (who looks exactly like Vilgax) gains powers. 47. The Color of Monkey – Simian returns. 48. Rook Island – Ben acts like a diva; Rook puts him in his place. 49. It's a Mad, Mad, Mad Ben World: Part 1 – Ben and Rook are stranded in a Mad Max-style dimension ruled by a mad Ben. 50. It's a Mad, Mad, Mad Ben World: Part 2 – They fight Mad Ben's tyrant rule.
Here is the definitive Ben 10: Omniverse episode list, organized by its official production cycles. Arc 1: A New Beginning
Episodes: 31–40 The season focuses heavily on the "Drama of the Time War" and Albedo's redemption/corruption arc.