Vengeance of Vilgax: Part 2

Plot
After the explosion, Gwen emerges from the rubble thanks to being protected by an energy shield. Then Spidermonkey and Chromastone emerge from rubble and leave. Ben, Gwen and Goop emerged. The aliens leave and they find Kevin who is now a mixture of things he had absorbed previously. Ben eventually notices that Chromastone, Goop, Spidermonkey and Way Big are missing from the Omnitrix. Azmuth suddenly appears as a hologram and is upset at the turn of events. He told Ben he had 24 hours to find the alien forms and recapture them so he could regain their powers. Outraged with the disaster, Azmuth also tells Ben that he'll never help him again.

Ben is upset and Kevin tries to revert to normal by absorbing Gwen's skin, but to no avail. Kevin then decides to use the Plumber's badges to track down the alien samples. The trio find Chromastone causing havoc in the pier and Kevin attacks. He discovers his new morphing powers and uses them to fight Chromastone. Ben tries to become Humungousaur but becomes Upchuck and captures Chromastone after Kevin knocked him out. The trio continues to search for the aliens and Ben wants to drive, upsetting Kevin. Gwen uses her laptop upgraded by Plumber technology to reveal Vilgax had beaten 10 heroes and now had their abilities. Ben is not worried but blames Kevin for the Omnitrix problems as Spidermonkey stops them using his webbing fluid and uses a web to take Gwen.

Ben becomes Brainstorm and frees Gwen and then fights Spidermonkey while Kevin uses his new powers to free Gwen from the webbing. He then absorbs Spidermonkey after Gwen reminds him and the trio continues their drive. The trio goes into the sewer and Goop shows up surrounding Ben. Goop defeats Kevin and Gwen with ease as Ben becomes Swampfire to battle Goop. The battle is then taken above ground after Swampfire's flames ignited methane in the sewers, causing a huge explosion. Goop is finally re-absorbed after a long fight.

The trio later goes after Way Big having only an hour before Ben had to battle Vilgax. Max contacts the group telling them Vilgax is one of the Plumber's enemies and he is getting into gear, wanting to fight him. Ben decides he would have to fight Vilgax without Way Big and he decides to go face Vilgax to stall. An hour later a massive newscrew has gathered and Psyphon appears. The battle is going to be seen on all planets and Vilgax's army surrounds the sky, going to destroy Earth if he won. Everyone on Earth watches and Ben arrives as Jetray, wanting Vilgax's team to be his servants after he won.

Vilgax appears and a fight ensues. Ben fights Vilgax as Jetray, Big Chill and then Humongousaur. But Vilgax is too strong and is going to kill Ben when Kevin and Gwen arrives with Way Big. Ben re-absorbs him and tries to use him but instead becomes Chromastone. The fight ends as Vilgax kills Ben with his sword just as Max arrives and Kevin and Gwen shares tears. Psyphon appears and takes the Omnitrix and Vilgax was going to absorb the Omnitrix's power. The pieces of Chromastone come together to form Diamondhead who easily man-handles Vilgax and Max approaches telling him the rules, as Vilgax is not allowed to come back to Earth and attack it again. Vilgax leaves but promises to have his vengeance upon Ben if he ever leaves Earth.

Ben was upset that everyone knew his secret and Max revealed he used his plumber tech to block half the fight and Ben had no idea what happened to Chromastone. He claimed the watch was broken and he decided teamwork was the best option regaining his friend's trust after saving the Earth.

Major Events

 * Ben has damaged the Omnitrix and loses Azmuth's trust.
 * Kevin gets mutated for the second time.
 * Chromastone reforms into Diamondhead after Vilgax destroyed Chromastone.
 * Vilgax loses the Conqueror's challenge and is banished from Earth.

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Kevin Levin
 * Max Tennyson

Villains

 * Vilgax
 * Psyphon

Aliens Used

 * Upchuck (Accidental transformation; selected alien was Humungousaur)
 * Brainstorm
 * Swampfire
 * Jetray
 * Big Chill
 * Humungousaur
 * Chromastone (Accidental transformation; selected alien was Way Big)
 * Diamondhead (first appearance in Alien Force)

Errors

 * When Diamondhead shot diamonds the first time, only three fingers were there instead of four.
 * Brainstorm's lightning is micoloured blue instead of yellow.
 * When Ben is about to transform into Brainstorm, his hand isn't on the spider web.
 * When Big Chill froze Vilgax, Vilgax was still speaking through the ice.
 * Before Chromastone blasted Vilgax, his eye was different.
 * When Diamondhead used the three big shards, His eyes were wrongly placed.
 * When Ben told Vilgax to leave, there were diamond remains behind him. In the next shot, there was nothing behind him, after which, the remains reappeared.
 * When Ben wasn't sure what happened to Chromastone, the sides of the Omnitrix were pasted and reversed in color.

​Allusions

 * This episode makes two allusions to urban legends. First, when Spidermonkey goes after Gwen, Kevin says it'll lay eggs in her head, then when the eggs hatch, they'll eat her brain. Second, Ben says that, in the sewer, there are alligators that people flushed down the toilet when they were babies.
 * The Casey-Kelly Accords are a reference to Joe Casey and Joe Kelly, two of the creators of the Ben 10 saga.

Trivia

 * Ben states that this episode takes place during the summer when he said "Nothing like a refreshing dip on a hot summer day". This means that the previous two seasons had Ben in 9th grade as most ninth graders are from ages 14-15.
 * This is the first time Upchuck's transformation is shown.
 * In the Australian and Indian Cartoon Networks both parts of "Vengeance of Vilgax" were joined together.
 * When the aliens are shown on the Omnitrix map, Alien X, Cannonbolt, Upchuck and Lodestar aren't shown.
 * Even though Vilgax was to never come back to Earth again by the rules of the Galactic Code of Conduct, he kept coming back and attacking the Tennysons.
 * Kevin remains mutated until The Final Battle: Part 2 where Max tells him that the energy from the Omnitrix kept him in that mutant form.
 * This two-part episode aired on the eighth anniversary of the 9/11 attacks.
 * It is revealed that Kevin is afraid of alligators and Gwen of spiders.