Ben enlists Kevin’s help to break the Omnitrix’s physical seal. The experiment backfires spectacularly:
Picking up directly from Part 1, Ben is facing a mandatory duel against , who has already conquered ten worlds and absorbed the powers of their greatest champions. Under the "Galactic Code of Conduct," if Ben loses, the Earth belongs to Vilgax.
By the end of the episode, the status quo is shattered. Ben has saved the world, but at the cost of his best friend’s humanity and the trust of his mentor, Azmuth. [S3E2] Vengeance of Vilgax: Pt.2
This wasn't the cyborg Vilgax of the past; this was a "Conqueror of Ten Worlds" with a vast array of powers, including flight, super strength, and wind breath, making him a more versatile threat than ever before.
Instead of unlocking Master Control, the Omnitrix resets, and several of Ben’s alien forms (including Chromastone, Goop, Way Big, and Spider-Monkey) are physically ejected from the watch as independent, mindless entities. Ben enlists Kevin’s help to break the Omnitrix’s
"Vengeance of Vilgax: Part 2" is the high-stakes conclusion to the two-part premiere of Ben 10: Alien Force Season 3. It marks a pivotal shift in the series, featuring a desperate power play, a significant change to the Omnitrix, and the return of Ben’s most iconic nemesis in his most powerful form. The Premise: Ben’s Back Against the Wall
Knowing his current roster isn't strong enough to stop this version of Vilgax, Ben ignores Azmuth’s warnings and attempts to to unlock the Master Control. The Turning Point: The Hack Gone Wrong By the end of the episode, the status quo is shattered
The episode culminates in a brutal showdown at a park. Ben is forced to recapture his escaped aliens while simultaneously fending off Vilgax.