Back with a Vengeance

Back With a Vengeance is the twentysixth episode of Ben 10, it's also the last episode of the second season.

Plot
The episode starts off with a big chunk of ice being carried on to the Megacruiser (from Grudge Match), which has been taken over by Kevin Levin. He figures out that the person contained within the ice is none other than Vilgax. When Vilgax is released, the two of them battle before Vilgax realizes that Kevin might be of some use to locate the Omnitrix. Meanwhile, while visiting Niagara Falls, Ben figures out the Master Control of the Omnitrix and is able to transform into any alien just by thinking about it and stay in the alien form indefinitely. Kevin and Vilgax locate Ben and fight against him together. Despite Ben's new abilites, the three of them arrive at a stalemate. Max attempts to trap the two villains in the Null Void, but Ben stops for a moment, but Vilgax pulled him in and ends up continuing his battle in the Null Void. Gwen goes after Ben but Kevin takes her hostage, forcing Ben to hand over the Omnitrix to save her. Ben shorts out the Master Control before he gives it to them but Vilgax reveals that he knows all of the secrets of the Omnitrix and he will be able to figure it out with ease. Kevin double-crosses Vilgax at that moment, allowing Ben and Gwen to retrieve the Omnitrix and escape the Null Void, trapping Kevin and Vilgax there. Ben reattaches the Omnitrix to his wrist but then remembers he can no longer access the Master Control and his abilities, complete with the Omnitrix malfunctioning and turning him into random aliens, are back to normal.

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Max Tennyson
 * Vilgax
 * Kevin Levin
 * Null Guardians

Aliens Used

 * Upgrade
 * Grey Matter (8x and last transformation selected alien was Wildvine)
 * Diamondhead 4x
 * XLR8 6x
 * Heatblast 5x
 * Wildvine 3x
 * Wildmutt 4x
 * Ripjaws
 * Stinkfly 6x
 * Fourarms 3x
 * Cannonbolt 2x

Trivia

 * Kevin 11 was stuck in the null void for 5 years after this episode.
 * First time wee see the Wildvine and Cannonbolt icon on the Omnitrix.
 * Cannonbolt is used two times in the episode, but has no lines.
 * Ben turns into alien 43 times in the episode.
 * First time we see inside the Null Void.
 * From the begining, Ben unlock the Master Control, but at the end its get zeroed out by Ben.
 * All the icons on the Omnitrix is shown three times in the episode.
 * Diamondhead and Fourarms both overpowered Vilgax in this episode.
 * The Plumber Null Void radar desing look like a Omnitrix.