Ben's misuse of the Omnitrix for personal gain gets the Tennyson's booted from a 4-star hotel. Chafing against Grandpa Max's subsequent punishment, Ben heads out on his own, with Gwen trailing after him. At an arcade, they come across Kevin, a savvy street urchin living on his own and answerable to no one, who shares in Ben's current disrespect for authority and self-centered sense of independence. The two hit it off. When Kevin runs afoul of some street toughs, Ben uses the Omnitrix to help him out, and the two soon partner up. As it turns out, Kevin, unlike Ben, is a natural-born superpower, able to absorb energy like a sponge, but as his callous disregard for others becomes apparent, their friendship turns adversarial, and Ben has a supervillain to contend with, able to absorb and copycat his alien powers.
—statmanjeff