When a villainous, dimension-hopping version of Ben Tennyson – one who has fully mastered the power of Alien X – begins erasing other Bens from existence, our prime timeline Ben must team up with multiple alternate versions of himself (including classic Ben, Gwen, and even a surprise cameo from the original voice actors). Together, they fight to stop the rogue Ben before he annihilates every last Ben in the multiverse.