Ben Tennyson was in a trip with his cousing Gwen and his grandfather Max, and in that trip he founded a alien divice similar to an watch, called Omnitrix, and that device can turn him into 10 different alien beings, and with those powers Ben uses it to become into a superhero, but after Vilgax knows his location he sends his soldiers to get the Omnitrix, but after one of them betray his partners and the failure of the mission, Vilgax goes to earth to take the Omnitrix by his own.
