Girl Trouble

Girl Trouble is the 25th episode of Ben 10: Ultimate Alien and it is the fifth episode of season 2.

Plot
The group go to Gwen's house in order to find a solution to stop Computron's minions from Dimension 12. When they go inside her room, they already find another girl on her bed. It turns out to be Sunny, a related member of the Tennyson Family and a cousin of Ben and Gwen.

Gwen tries to persuade her mother to get rid of Sunny, but she explains that Sunny is staying over the summer because her parents want her to be around a good influence like Gwen. Sunny tries to flirt with Kevin and is forced to go with them to stop an invasion of Dimension 12 robots and she annoys all of them during the car ride. When they arrive at the location the robots are appearing, they fight them, with Ben becoming Four Arms. Sunny sees the commotion happening and gets out of the car to see. She then reveals her Anodite powers and destroys the rest of the robots, shocking everyone.

Gwen's mother is informed of Sunny's Anodite powers and thinks of whether she should stay or not, considering her dislike for Anodites. Suddenly, they get a visitor and it is revealed to be Sunny's boyfriend Antonio, who she always kept talking about, but Antonio is really a giant, caveman-like alien with little intelligence.

Sunny decides to run away with Antonio, and before they could go after them, Ben informs Gwen of another attack of the Dimension 12 robots. The robots plan to use a particle accelerator on a small canister bomb to make its energy levels stronger in order to blow up the whole planet. Ben transforms into Lodestar and they atack the robots again, before Sunny and Antonio join the fight.

Kevin shuts down the particle accelerator by smashing its control device and when they try to get Sunny to go back home, Sunny refuses to and sheds her human skin, revealing her Anodite form. When Gwen threatens to tell Sunny's parents about her misbehaving, a fight ensues. Gwen fights Sunny, Ben fights Antonio as Humongousaur and Kevin is in charge of making sure the upgraded canister bomb doesn't blow up and destroy them all.

Sunny overpowers Gwen (it should be noted that Sunny was in her full anodite form while Gwen chose not to use it against her cousin indicating she was a bit reluctant to show her full power) and Antonio's strength is too much for Ben, so he transforms into Ultimate Humongousaur and quickly gains the upper hand, while Gwen called her grandmother Verdona through a mana field.

Ben, as Ultimate Humongousour, tricks Antonio by picking up an unlit lightpost, while Antonio picked up a lit lightpost that made him get electricuted and knocked him out. Kevin disarms the bomb by pulling its cord. Before Sunny could finish off Gwen, Grandma Verdona arrives and overpowers Sunny, trapping her in her own shield.

She also takes the unconscious Antonio, and says that their parents are going to have to sort out everything. Verdona says good-bye and claims that Gwen's powers have suited her well even with the lack of formal training, citing the fact that Gwen was able to contact Verdona via the intergalactic Mana Field and offers her another chance to go to Anodyne with her to practice her powers but Gwen turns the offer down yet again. Verdona leaves with Sunny and Antonio and the group go to clean up the robots' mess from the battle against Sunny and Antonio.

Major Events

 * Ben and Gwen meet their anodite cousin, Sunny.
 * Sunny appears to be a much stronger anodite than Gwen.
 * Sunny starts to cause a lot of trouble, and fights Gwen causing a rivalry between them.
 * Verdona and Lili Tennyson return for the first time since Alien Force.
 * Because of this episode taking place during the summer, it now marks the 6th anniversary that Ben got the Omnitrix.
 * Sunny is sent home early for being a spoiled brat as quoted by Verdona.

Characters

 * Gwen Tennyson
 * Ben Tennyson
 * Kevin Levin
 * Verdona Tennyson
 * Lili Tennyson

Villains

 * Computron's Minions
 * Antonio (last part)
 * Sunny (last part)

Aliens Used

 * Four Arms
 * Lodestar
 * Humungousaur
 * Ultimate Humungousaur

Errors

 * In one scene, the Black 10 emblem on Ben's jacket is white and the 10 is in black text (same like in episode Duped).
 * If you look closely when Antonio is throwing Humungousaur, Humungousaur's toes are the same color as his scales.
 * When Ben transforms into Lodestar his voice was higher than usual and his eyes are way bigger than usual.
 * When Kevin is trying to stop the bomb from becoming more powerful, the on-off switch look alikes are all set to the off position. As soon as the camera changes to a few frames before Kevin smashes the machine, one switch is set to on.
 * Fourarms has a slightly different transformation.
 * In the transformation of Fourarms, in one part he has 3 fingers on each hand, the producers might have fused some fingers by mistake.
 * When Ultimate Humongousaur fired his missiles at Antonio, the missles didin't explode, they just shot at Antonio.

Trivia

 * There is a running gag in this episode that the tone that most of the characters speak in a bratty way.
 * In this episode Lodestar's voice sounds like the battle droids in the Star Wars saga.
 * This is the second time Gwen fights one of her cousins. First being in Absolute Power: Part 1 against Ben.
 * When Ben kicked Antonio into the goalpost, he kicked a goal in general.
 * This episode reveals that Ben and Gwen have another set of aunts and uncles, specifically on their grandmother's side.
 * Ben has now used all of his previously seen ultimate forms in this season, however Ultimate Wildmutt has yet to make an appearance.
 * This episode is set during the summer indicated by one of Gwen's conversations with her mom.
 * This is the third time Gwen and Ben has fought an Anodite. The first time being Verdona in What Are Little Girls Made Of, The second being Absolute Power: Part 2, where Ben fought Gwen.
 * This is the second time Ben called someone other than Gwen a doofus, the first one was Kevin in The Enemy of My Enemy.
 * This is the second time when someone calls Gwen Kevin's girlfriend as the first was in Pet Project.
 * This is the first time an Ultimate called someone a "doofus".
 * This is the second time Kevin mocks Gwen. The first time was in Ben 10: Alien Force in Primus.
 * This is the first that Ultimate Humungousaur appears without Jetray.