X = Ben + 2

X = Ben + 2 is the thirteenth episode of Ben 10: Alien Force, it's also the last episode of the first season.

Plot
After Sevenseven kidnaps Princess Attea, her father sends his high commander Ralph on Earth, in order to look for Attea and then destroy the planet. Ralph decides to contant Kevin who's friends with and thanks to Gwen's power the group quickly locates the kidnapped princess.

When they reach them, Sevenseven destroys a dam and Ben decides to try the untested Alien X, easily fixing the broken dam and reverting every damage thanks to the alien's reality-warping abilities. But after that Ben finds himself locked inside Alien X because of the eternal debates between the two entities who control its body, Serena, the voice of love and compassion, and Bellicus, the voice of rage and aggression.

While Ben is trapped inside Alien X's body, Kevin and Gwen have to protect him and try to stop Attea's father from destroying Earth. But when Princess Attea with the help of Sevenseven turns against her father to overthrow him, Kevin and Gwen get inprisoned and Attea is ready to destroy the Earth. Finally Ben manages to convince Serena and Bellicus to let him transform into another alien, and as Swampfire he rescues both his friends and his planet.

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Kevin Levin
 * Sevenseven
 * Princess Attea
 * Emperor Milleous
 * Commander Raff

Aliens used

 * Alien X
 * Swampfire

Quotes

 * Swampfire: (Inkersian warrior drops because of smoke) Now that's just rude. I don't smell that bad, do I? (smells his armpit)


 * Kevin: (absorbs Seven-Seven's armor) Nice armor! (punches him in the face)


 * Kevin: (trying to put Alien X through a rear car window) Ugh, just bend or something!
 * Gwen: (Kevin tries to stuff Alien X in the trunk) You can't just stuff him in the trunk!
 * Kevin: You're right; he doesn't fit.
 * Gwen: I'm serious. He hasn't moved since he fixed the dam. Maybe he's hurt, or...
 * Kevin: Nah, he's warm. Maybe he's resting.

Trivia

 * We got to knew that somewhere in the universe Vilgax is there because Sevenseven is a Bounty Hunter replacing Sixsix so Vilgax is sending his Bounty Hunters on Earth but this not rummored anywhere this is the fact which we should mark out ourself.
 * While transformed into Alien X, Ben is considered the voice of reason.
 * Alien X's voice is made of three voices mixed up together. So three voice actors (one actress) has played the voice of Alien X.
 * Serena and Bellicus are Latin words that mean "calm" and "war-like".
 * Tara Strong, the voice actress who played Ben in the first Ben 10 series, guest stars in this episode as the voice of Princess Attea.
 * We discover that Gwen not only has the ability to track where someone is, but she is also able to see what he/she is doing at the time.
 * This episode marks the only time Ben uses Alien X.
 * The fact that, at the end, Pluto was destroyed instead of Earth, might be an allusion to The Fairly OddParents episode, "Vicky Lose Her Icky". At the end, Cosmo presses a "planet-destruction-switch" and Pluto was destroyed, because the switch didn't have a specific planet.