Trade-Off

Trade-Off is the thirty-seventh episode of Ben 10: Alien Force.

Plot
Kevin and Darkstar find a mysterious artifact called the Dominus Librium that could return them to their previous forms, but do not consider the consequences. Kevin loses his powers and regains his human appearance as does Darkstar. Gwen finds out what he did and goes to fight Darkstar, but Michael uses the libruim and and starts absorbing her energy. Kevin and Ben come to help but Darkstar absorbs Bens energy aswell. Since Kevin can't do anything he grabs the librium which overloads and explodes. Because of this, Kevin was turned back to his previous mutation as it's the same with Darkstar who vows to get revenge. Then Kevin, Gwen, and Ben go to Mr. Smoothy.

Major events

 * Darkstar returns and makes an offer to Kevin to return to their original forms.
 * Kevin returns to his human form but loses his powers to Darkstar.
 * Kevin reverts back to his second mutated form again.

Main Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Kevin Levin (Main character in this episode)

Villains

 * Darkstar
 * Forever Knights

Aliens used

 * Jetray
 * Big Chill (Accidental transformation; selected alien was Humongousaur)
 * Echo Echo (Accidental transformation; selected alien was Jetray)
 * Swampfire

Quotes

 * Darkstar: Can't you feel it? The Librium is transferring your excess power into me.


 * Kevin: It... hurts!


 * Darkstar: Nothing... worth having is gained... without effort!


 * Gwen: (To herself) Michael's mana led me to him like a beacon. He's inside, I can feel it. (Makes steps out of mana and walks over fence and enters Michaels lair ready to fight)
 * Michael: (Sees Gwen in mirror from admiring his face) Ah, lovely Gwen. I've been expecting you.
 * Gwen: I'll just bet you have. Kevin's aura stinks of you. Tell me what you did to him and maybe I'll go easy on you. (Mana's color gets more intense)

Trivia

 * The Dominus Librium may have come from equilibrium meaning balance.
 * When Kevin returns to his human form, he is seen with briefs.
 * This episode is the second time (since the events of In Charms Way) Kevin has been manipulated by an enemy of Gwen's into helping them, in exchange for returning to his normal self, only to be betrayed by said enemy, who immediately aims to steal Gwen's powers.