The Enemy of My Enemy

Not to be confused with Enemy of My Frenemy

The Enemy of My Enemy is the eighteenth episode of Ben 10: Ultimate Alien.

Plot
In a small hut, the Vreedle Brothers' father speaks with Argit, saying that he enlisted them to the Plumbers' Academy, but are failing in their exams. He is sending Argit to change their scores or he shall get a bad punishment for not doing so.

While taking a ride in Ben's car, Ben and Gwen discuss that Ultimate Kevin is still continuing his rampage on everyone that wronged him and that he needs to be taken care of. Just then, Ben accidentally runs over Argit, but he survives. Argit explains that he needs their help in order to hide from Ultimate Kevin, who he met earlier when he came to Earth for some supplies from him, but Ultimate Kevin attacks him for all of his double-crossing, and eventually, Argit was able to escape. Argit says that they need to hide him from Ultimate Kevin, so they suggest a few places until they settle on the Plumbers' Academy, which Argit only agrees to go to because he needs to fulfill his promise to Mr. Vreedle. While on the way there, Ultimate Kevin attacks them. Ultimate Kevin uses Big Chill's intangibility and goes inside the jet, asking for Argit. Ben becomes Jetray and battles Ultimate Kevin, but Ultimate Kevin is too strong. Gwen activates the air-lock, which sends Ultimate Kevin out of the jet, but he only leaves them so he can save his falling car.

The group arrive at the Plumber's Academy, where they are greeted by the headmaster, Magister Korwak, but he is not happy to see Argit with them. Korwak orders Plumbers to take Argit to a cell, while he talks to Ben and Gwen about bringing Argit here so he can escape from Ultimate Kevin. Meanwhile, Argit fakes having to go to the bathroom, with his escort taking him. Before he could realize it was a trick, Argit uses his quills to stun him. Argit then begins looking around for the students' grade room, but unfortunately ends up in a cafeteria filled with students. The Vreedles are also there and Argit tells them about their plan, but to keep a low profile by acting like they don't know who Argit is. Argit does find the room and changes the scores, but the Plumbers' Academy is shocked when Ultimate Kevin arrives.

Ben and Gwen confront Ultimate Kevin when he goes inside and attacks the students. Ben becomes Humungousaur to fight Ultimate Kevin, but Ultimate Kevin is stronger. Humungousaur evolves into Ultimate Humungousaur to fight Ultimate Kevin, but Ultimate Kevin still has the upper-hand and defeats Ultimate Humungousaur. As Ultimate Kevin was about to kill Ben, Gwen tries to stop him while Ultimate Kevin begins arguing with her. Then, Ultimate Kevin sees Argit, which makes him remember why he is here and tries to get Argit. Argit quickly runs back to the Vreedles and tells them he needs their help to fight Ultimate Kevin and the Vreedles unzip a bunch of weapons. Argit and the Vreedles come back and Ultimate Kevin begins throwing Argit around the room in a hard way. The Vreedles launch a bomb at Ultimate Kevin, but had no idea that the bomb will destroy the school and everyone inside it. Ben wakes up and transforms into Echo Echo to stabilize the bomb using sonic screams, but it doesn't work, so Echo Echo evolves into Ultimate Echo Echo and takes the bomb, using his sonic disks, into space and holds it together until it's a safe distance away, where he lets it explode. As Ultimate Kevin was about to finish Argit off, Gwen stops him, causing Ultimate Kevin to get really mad, but a little bit of his sanity makes him spare Gwen's life. Ultimate Kevin leaves, thinking that Argit was dead, but Argit was able to shut off his pulse so Ultimate Kevin would think he was dead. Korwak orders the Vreedles to arrest Argit for assault of two cadets and 14 acts of warrants for his arrest, and Ben and Gwen wonder if Ultimate Kevin could really become sane and normal again.

Major Events

 * The Vreedle Brothers appear for the first time since Ben 10: Alien Force.

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Magister Korwak
 * Vreedle Brothers
 * Octagon Vreedle
 * Rhomboid Vreedle
 * Plumbers
 * Pops Vreedle

Villains

 * Ultimate Kevin
 * Argit

Aliens Used

 * Jetray
 * Humungousaur
 * Ultimate Humungousaur
 * Echo Echo
 * Ultimate Echo Echo

Errors

 * When Ben is talking to Gwen in his car, he loses the stripes in his right sleeve.
 * In one of the scenes where Ben is talking to Gwen, his tongue is the same color as his skin.
 * In the scene where Ben, Gwen and Argit are discussing where they're going to hide Argit, Gwen's collar was red instead of white.
 * The episode keeps switching between Argit's jacket having a line on either side and having one line on the left side
 * As Humungousaur turned into Ultimate Humungousaur, the 4 spikes are not popping out of the right sides of his Ultimatrix symbol.
 * In the scene where Ultimate Echo Echo was flying, one time he has light blue colored feet, like his shoulders, and another time he has blue feet like his regular skin.
 * In some scenes, when Ultimate Humungousaur is fighting Ultimate Kevin, the Big Chill 'hood' is not on his head.

Allusions

 * This episode is from the expression "The Enemy of My Enemy is My Friend."

Trivia

 * FusionFall released an Ultimate Humungousaur set in relation to this episode.
 * It is revealed that Argit's species can shut off their pulse.