The Forge of Creation

The Forge of Creation is the sixteenth episode of Ben 10: Ultimate Alien.

Plot
With Ultimate Aggregor having all four pieces of the Map of Infinity, it looks like his plan will come to fruition. Azmuth scolds Ben, Gwen, and Kevin for failing to stop him. As Azmuth believes that all hope is lost, Ben says there is still another way to stop Ultimate Aggregor. He says that Kevin has kept a security system to prevent the transformation into Alien X, so Gwen and Kevin gave Ben their keys and unlocked Alien X, then Ben transformed into him.

Inside Alien X, Ben tried to get the attention of Serena and Bellicus. As they begin arguing over minor things, Paradox suddenly appears, making the two personalities furious and they attempt to destroy Paradox, as he is prohibited to be within 500 light years of them, until Paradox is able to turn Ben back to normal and out of Alien X. After some arguing between each other, Azmuth and Paradox explain that Aggregor's plan was to use the Map of Infinity to enter the Forge of Creation, where Celestialsapiens, like Alien X, are born. Ultimate Aggregor is intent on absorbing the powers of a newborn Celestialsapien that has not developed multiple personalities, and with that power, he can easily conquer the universe. Paradox brings Ben, Gwen, and Kevin to the entrance to the Forge of Creation, where he leaves them as he cannot go there. Soon, the group is attacked by Ultimate Aggregor's drones and Terraspin is able to get rid of them. Unfortunately, Kevin's jet hits a wedge in the time barrier and Ben accidentally falls in, only to be saved by Gwen. But Ben just realizes he has brought his ten-year-old self with him.

Young Ben recognizes Kevin and still believes him to be evil. He transforms into Heatblast and fights Kevin. Ben tries to become Big Chill to stop Young Heatblast, but becomes NRG instead. Soon, they reason with young Ben, explaining that Ben is his older self and that Kevin is no longer evil. Young Ben insults Gwen like in the original series. With no way to get young Ben back to his own time, he is forced to join the others. Along the way, young Ben admits why he was so obnoxious six years ago and looks through the Ultimatrix, seeing how "lame" the aliens except Humungousaur are. They reach the Forge of Creation, filled with many Celestialsapiens, frozen in place. They come across an even bigger female Celestialsapien, holding a baby Celestialsapien in her hands. But then, Kevin's jet crashes and they crash into the mother Celestialsapien's hands.

Both Bens become Four Arms to break free. Ultimate Aggregor suddenly approaches them and easily defeats them. Four Arms turns young Four Arms into young Stinkfly to distract Ultimate Aggregor, while Four Arms becomes Swampfire, then Ultimate Swampfire to fight Ultimate Aggregor. But Ultimate Aggregor is still too powerful and defeats both Bens. Young Ben says that Kevin could absorb his Omnitrix, but Kevin says that "he better go with the A-game" and instead chooses to absorb the Ultimatrix, becoming Ultimate Kevin. He prevents Ultimate Aggregor from absorbing the baby Celestialsapien's powers and absorbs his powers, turning Ultimate Aggregor back to normal.

Ben, Gwen and Young Ben prevent Ultimate Kevin from finishing off Aggregor, but by absorbing the energy of the Ultimatrix, he has become insane once more. He even thinks about absorbing the baby Celestialsapien himself, but young Ben complains that Ultimate Kevin is a jerk and is too busy feeling sorry for himself that he does not notice people try to be nice to him. Ultimate Kevin leaves them, promising to "come back". Paradox appears, telling them he is sending young Ben back home and will think the whole adventure was a dream. Gwen tells young Ben to be nice to young Gwen and kisses him on the cheek, much to young Ben's embarrassment. Paradox leaves with young Ben, and now Ben and Gwen's current mission is to return Ultimate Kevin to normal.

Major Events

 * The gang meets up with 10-year-old Ben.
 * Aggregor is stopped by Kevin.
 * Kevin mutates and goes insane once again.
 * NRG makes his debut.
 * Alien X makes his Ultimate Alien debut.
 * Bellicus and Serena make their Ultimate Alien debuts.

Ultimatrix Alien Debuts

 * NRG
 * Alien X

Characters

 * Ben Tennyson (10 and 16 years old)
 * Gwen Tennyson
 * Kevin Levin
 * Professor Paradox
 * Azmuth
 * Bellicus (first re-appearance)
 * Serena (first re-appearance)
 * Baby Celestialsapien (first appearance)
 * Mother Celestialsapien (first appearance)
 * Celestialsapiens (first appearance)

Villains

 * Ultimate Aggregor
 * Ultimate Kevin
 * Ultimate Aggregor's Soldiers

By 16 year old Ben

 * Alien X (first re-appearance)
 * Terraspin
 * NRG (first appearance; accidental transformation, selected alien was Big Chill)
 * Four Arms (accidental transformation, selected alien was Big Chill)
 * Swampfire
 * Ultimate Swampfire

By 10 year old Ben

 * Heatblast (first re-appearance by 10 year old Ben)
 * Wildmutt
 * Four Arms (accidental transformation, selected alien was Upgrade)
 * Stinkfly (first re-appearance by 10 year old Ben)

Errors

 * Like in And Then There Were 10 and many other episodes of the original Ben 10 series, 10 year-old Ben's Omnitrix contains an error. The button used to activate the alien selection dial is on the wrong side of the Omnitrix, facing outwards. The button is supposed to face towards Ben for ease-of-access and has mistakenly been put on the outside, or on both sides as seen in And Then There Were 10.
 * In the scene where young Ben is looking through the Ultimatrix, it is coloured like the Omnitrix.
 * When Ultimate Kevin grabs Ultimate Aggregor's head, before absorbing his powers, his Rath claw is the same color as his left arm and hand, and also changes to Armodrillo's armor color when he shoots Jetray's neuro blasts right in his face before he absorbed his powers.
 * When Ultimate Aggregor throws young Four Arms into the air, if you pause it at the precise moment before he hits 16 year-old Four Arms, his eyes are miscolored green instead of yellow.
 * When Ultimate Kevin jumps to fly away from the mother Celestialsapien, his legs are blue along with his pants.
 * In the scene in time barrier, Gwen's collar was red instead of white.
 * When 16 year old Ben is first talking to young Ben his jacket is shown to have stripes on either side.
 * For a split second, Terraspin is missing a hole on his body.
 * When Kevin is introducing himself to young Ben, the part of the jacket between the two shoulder stripes of Ben's jacket is black instead of green.
 * When young Ben turns into young Heatblast, the silhouette shown is crooked.
 * When Ultimate Aggregor reaches for the baby, he uses his left hand. However; in the next scene he is reaching with his right.
 * During the battle with Ultimate Aggregor, Kevin is shown running away. The next time he is shown, Kevin's knocked out despite not actually fighting Ultimate Aggregor.
 * When Ultimate Aggregor throws young Four Arms, his Omnitrix symbol is on the wrong shoulder.
 * When both Bens used Four Arms, 16 year-old Four Arms' eyes were miscoloured yellow.
 * When Gwen kisses young Ben, his Omnitrix is light green and red.

Trivia

 * According to Dwayne McDuffie, the Celestialsapiens had taken notice of Ben's, his friends and Ultimate Aggregor's presence, and they were debating over what to do.
 * When someone asked if the "next universe over" was our universe, Dwayne replied with "It would've been funny if it was..."
 * Tara Strong returns to voice young Ben.
 * Paradox hints that Ben will one day gain control of Alien X.
 * This was proven true in So Long, And Thanks For All The Smoothies where Ben successfully uses Alien X to recreate the universe.
 * This episode reveals that there are other universes.
 * Dee Bradley Baker replaces Steve Blum as young Heatblast, and reprises young Stinkfly and Wildmutt, but John DiMaggio voices young Four Arms.
 * When Ben and the others enter the Forge of Creations there is a homage to the famous picture of Hubble: "Pillars of creation".
 * In the Malay dub of this episode, the scene where young Ben teases Gwen and Kevin's joke about how baby Celestialsapiens are born have been deleted for slightly suggestive dialogue.
 * In the Indian version of this episode, Kevin's suggestion about what happened to Gwen, the butt joke, the baby Celestialsapien joke and even the part where young Ben calls Kevin a jerk are censored.
 * In the Latino American version of this episode:
 * Celestialsapiens are called "Celestials."
 * In the butt joke, "butt" is removed.