The Ultimate Enemy: Part 2

The Ultimate Enemy: Part 2 is the fifty-second episode of Ben 10: Ultimate Alien and the twentieth episode in the third season. It is the series finale of Ultimate Alien.

Plot
Vilgax betrays Diagon so that he can absorb all of his power to destroy his one true enemy: Ben Tennyson.

Major Events

 * Ultimate Way Big makes his first appearance.
 * Sir George and Diagon are both killed in this episode.
 * Vilgax absorbs Diagon's powers.
 * Ben defeats Vilgax by using Ascalon.
 * Vilgax tempts Ben into using Ascalon, the Ultimatrix and Diagon's power to rule the world, but he later snaps out of it thanks to Julie.
 * Ben and Julie share their first kiss.
 * All of the Esoterica turn human again thanks to Ben with Ascalon.
 * Azmuth cuts off the Ultimatrix from Ben so that he could give him a new Third Omnitrix.

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Kevin Levin
 * Sir George (Killed by Diagon)
 * Azmuth
 * Julie Yamamoto
 * Ship

Villains

 * Diagon (Absorbed by Vilgax and killed by Ben)
 * Vilgax
 * Psyphon
 * Flame Keepers' Circle
 * Esoterica

Aliens Used

 * Jury Rigg
 * Way Big
 * Ultimate Way Big (First and only appearance in Ultimate Alien)
 * Wildmutt
 * Ultimate Wildmutt
 * Chromastone

Trivia

 * This episode was dedicated to Dwayne McDuffie, one of the writers and story editors, who passed away in 2011.
 * After Ben defeated Vilgax, Vilgax turns back into his Alien Force outfit, which is strange since he lost them in The Final Battle: Part 2.
 * This episode includes flashbacks from Alien Force and Ultimate Alien.
 * This is Ultimate Wildmutt's second appearance.
 * At the end of the episode, Ben asks Azmuth if he can get Master Control for the new Omnitrix, then Azmuth just smiles and says that he might get it as a gift for Ben's 18th birthday.
 * A sneak peek of Ben 10: Omniverse appeared after this episode.