16. The Forge of Creation

Complete story — includes the ending

On Galvan Mark II, Azmuth chastises Ben, Gwen, and Kevin for their failure to stop Aggregor from acquiring the completed Map of Infinity. Ben decides to turn into Alien X, his most powerful alien form possessing virtual omnipotence, in the hopes of stopping Aggregor; however, Ben is unable to convince Alien X's split personalities to cooperate, and Professor Paradox ultimately reverts Ben to human form. Paradox explains that the Forge of Creation is the birthplace of Celestialsapiens, the species of Alien X; Aggregor intends to absorb the powers from an infant member of their species, which will give him infinite power. Paradox teleports the team to the Forge of Creation, which is out of sync with time itself due to a chrono-randomization barrier. When Ben falls through the barrier, he accidentally summons a ten-year-old version of himself, who agrees to help them stop Aggregor. In the center of the Forge of Creation, the team battles Aggregor on the palm of a mother Celestialsapien, but all of them are defeated. As a last resort, the ten-year-old Ben convinces Kevin to absorb the Ultimatrix's power, turning him into a monstrous amalgamation of Ben's aliens. Kevin easily defeats Aggregor, but loses his mind and flees. Paradox returns the young Ben to his timeline, while the old Ben resolves to find and rescue Kevin. Omnitrix alien debuts: Heatblast (10 years old), Wildmutt (10 years old), Four Arms (10 years old), Stinkfly Ultimatrix alien debuts: Alien X, NRG