Aggregor is the main antagonist of Season 1 of Ben 10: Ultimate Alien. He is an alien Warlord who seeks 5 aliens in order to absorb their powers so he can Obtain the Map of Infinity allowing him to enter the Forge of Creation so he can absorb the powers of a Baby Celestialsapien, and use it to become Omnipotent and conquer the Universe. He is voiced by John DiMaggio.