Duped

Duped is the second episode of Ben 10: Ultimate Alien and the 100th episode overall.

Plot
The Forever Knights try to invade the museum using an alien paramilitary tank, but they're interrupted by Ben as Rath. Gwen calls Ben and tells him that he's missing Julie's tennis game. Ben sees the Forever Knights running away, gets angry, and tears apart their tank, then heads to the stadium for Julie's game. When Julie is about to begin her match, Ben shows up and makes a huge hit of himself and blows her concentration. Julie and Gwen get mad at Ben for showing up late. Kevin wants to investigate why the Forever Knights tried to rob the museum, but Gwen disagrees on going, stating that they're probably stealing some tech to rule the Earth. Ben also wants to catch the Sumo Slammers movie, but Gwen tells him not to. She tells Ben he can't be in two places at once.

Ben then comes up with a plan and transforms into Echo Echo and splits into three, then turns back and this time there are three Bens. One of them is the logical Ben, the second is the sensitive Ben and the third is the immature and arrogant Ben. However, he doesn't know this. The logical Ben goes to the Sumo Slammers 3-D movie, the sensitive Ben goes with Kevin to investigate the Forever Knights robbery, and the immature Ben stays to watch Julie's match. The Forever Knights, meanwhile, and their king Urien find a shortcut to the museum to claim ultimate power. Unfortunately, immature Ben keeps embarassing Julie, much to the annoyance of her and Gwen, sensitive Ben keeps annoying Kevin by blabbing about feelings, personal issues and tight subjects. Kevin then has it when he was talking how Gwen and him are together and Ben telling him since that his cousin and says that they might become a family...eventually Kevin says, "BEN, you've always been kinda girly, but today, you're CREEPING ME OUT!!!!" but the logical Ben is having a good time at the movies or at least so far. Kevin and sensitive Ben fall into the basement of the museum and meet Urian and his Forever Knights. Urien makes his minions fight Intimate Ben and Kevin, where he's still annoying Kevin due to his personality, e.g. he says to Urien,"Excuse me, sir, but the signs clearly say do not touch the exhibits (holding up the sign)". They knock Urian's minions out and find out that he's after an Toltech Battle Armor, which he uses to attempt kill sensitive Ben and Kevin. This is sensitive Ben's fault, because he stalled Kevin, saying that enemies were people, too, while Urien assembles the Aztec alien battle armor. The sensitive Ben calls logical and immature Ben for backup. The two Bens hurry to the museum to help sensitive Ben and Kevin. When Kevin sees all three Bens, he responds with," If I wasn't running for my life, I'd demand an explanation!" Sensitive Ben and logical Ben try to explain, but at the end, immature Ben cuts them off by saying, to Kevin "What's it to you?" and Kevin repeats that he's running for his life.

Then, all three Bens change into Big Chill, Upchuck and Cannonbolt to fight Urien but fail due to their weaknesses and differences, e.g. Cannonbolt slips on Upchuck's slime. So all the Bens change into Echo Echo, and go back into one Ben. Ben uses Lodestar to finally stop Urian. Even though Julie won the tournament, she's was upsetting at Ben thanks to his arrogant clone embarassing her. She kindly asks Ben to make it up for her by taking her to see the Sumo Slammers 3-D movie, but Ben tells her that he saw it during her match, which causes Julie to be very furious. She and Gwen storm off in disgust along with Kevin, leaving Ben all alone to repent for what he has done in order to gain back their trust.

Characters

 * Ben
 * Gwen
 * Kevin
 * Julie

Villains

 * Forever Knights

Aliens used

 * Rath (transforms off-screen)
 * Echo Echo (x2)
 * Upchuck
 * Big Chill
 * Cannonbolt
 * Lodestar
 * Humungousaur

Errors

 * When arrogant Ben steps out of the bathroom, the black "10" emblem on his jacket is white and the 10 is in black text.
 * Strangely, when Gwen is calling Ben, Rath suddenly pulled a phone out of nowhere even though doesn't have pants on like Ben does. This is a rare moment of "Mallet Space", in which a character pulls an object seemingly from nowhere.
 * When one of the three Bens transformed into Big Chill, before he exclaimed Big Chill, his legs were missing.

Trivia

 * Kevin subtlely hints he's had past girlfriends by saying sarcastically to Ben "Here's a hint, ask me for girlfriend advice.", he does so again in Revenge of the Swarm but that time, its more directly.
 * This is the first- and probably only- time Humongousaur sang.
 * Ben's middle name is revealed to be Kirby in this episode.
 * This is the first episode that Ben didn't turn into any Ultimate aliens.
 * Intimate Ben sang Humongousaur instead of simply yelling Humongousaur, much to Kevin's annoyance.
 * When Gwen was asking Arrogant Ben where he was after he exited the bathroom, he notes that this is a "Ben Classic". This is a reference to his arrogant and immature personality in the original series and the third season of Alien Force.
 * Julie is the fourth person to be offended with Ben's immaturity and arrogance. The first being Gwen, the second being Kevin and the third being Azmuth.
 * This is the only known time that Ben uses multiple aliens at the same time, aside from Ben's fusion aliens in Dr. Animo and the Mutant Ray.
 * It becomes public that Ben and Julie are a couple.
 * The ending of this episode where Ben regrets going to the movies during Julie's match is a reference to In Charm's Way where Kevin regrets getting mad at Gwen after Ben tells him she's been working on a cure for his mutation, but back then Kevin hurt Gwen even more while Julie was just upset at Ben.
 * This is the second time Ben used multiple aliens to get him in two places at once by using Echo Echo, the first was Ditto in Divided We Stand.
 * This episode featured a third faction of the Forever Knights led by King Urien, who appears to be the most merciless as he kills one of his own men for questioning him.
 * In retrospect, the sensitive Ben should have been with Julie, the logical Ben should have been with Kevin, and the immature Ben to the movies. If this was the case, the episode could have gone off without a hitch. Or the real Ben goes with Julie, the immature with Kevin and the sensitive Ben to the movies.
 * Kevin seemed to notice something was wrong with Ben: he sees immature Ben with Gwen, and then sensitive Ben taps him on the shoulder! Even stranger, when he asked Ben," Didn't I just see you with Gwen?", Ben replies with an unreassuring,"I guess you did." Kevin has always seemed one for noticing details, like noticing that Ben's left eye twitches when he tells a lie.
 * Before becoming one again, 2 of the Ben's used Upchuck (Arrogant) and Cannonbolt (Intimate) which appeared in all 3 series.
 * This was the second time Kevin fainted. The first was in Con of Rath in Alien Force.