|The Ultimate Enemy: Part 2|
|Original broadcast||March 31, 2012|
|Series||Ben 10: Ultimate Alien|
|Overall episode number||150|
|Written by||Dwayne McDuffie|
|Directed by||Dan Riba|
The Ultimate Enemy: Part 2 is the fifty-second episode of Ben 10: Ultimate Alien and the twentieth episode in the third season. It is the second part of the series finale of Ultimate Alien.
The episode starts off from where the previous episode left off. The Team, Sir George, Vilgax and Psyphon look out through a hole in the cave to see the gigantic Diagon hovering outside after breaking the Seal. They head outside to confront him. Diagon claims that he won't need to fight the Team and George, calling Vilgax to do away with them. However, Vilgax has vanished, leaving George to comment Vilgax is wise for knowing that Diagon will be defeated. Undeterred by this, Diagon simply summons droves of Esoterica in Vilgax's place and has them begin attacking, with their focus solely on George. Gwen and Kevin decide to keep them busy so George can fight Diagon.
Ben, seeing Jury Rigg is no match for Diagon, transforms into Way Big. However, before Way Big can finish his quip, Diagon cuts him off, gloating how he believes he will defeat him and conquer our dimension. Way Big finishes his quip and transforms into his Ultimate version, growing to a fraction of Diagon's size. Jumping on Diagon's face, Ultimate Way Big begins pummeling him, much to Diagon annoyance. Tossing Diagon into a dam and destroying it in the process, Ultimate Way Big begins shooting cosmic rays and discs at his foe, accidentally destroying some property when he loses his balance momentarily. However, none of Ultimate Way Big's attacks cause any significant damage to Diagon.
Annoyed by Ultimate Way Big's attempts to stop him, Diagon creates a small acid storm over Ultimate Way Big, harming him enough to cause the Ultimatrix to time out, leaving an unconscious Ben in the water.
Elsewhere, Gwen and Kevin have become overwhelmed by the seemingly endless amount of Esoterica, leading Gwen to cast a protective shield to block them. Diagon appears before them, leading Gwen to think Ben may be deceased. However, Kevin assures her that Ben might have simply just changed back. George declares Ben's sacrifice will not be in vain and resumes fighting Diagon, giving him several slashes to the face while Gwen and Kevin resume fighting the Esoterica.
Back at the dam, Ben recovers and transforms into Wildmutt, then into Ultimate Wildmutt to head back to the battle. Arriving, Ultimate Wildmutt helps Gwen and Kevin defeat the Esoterica, defeating all of them.
Meanwhile, Vilgax impatiently tells Psyphon to hurry with the machine's preparations. However, Psyphon tells Vilgax that he needs to properly adjust the device as it is not like absorbing just the powers from a being like he had previously done. Vilgax then threatens him to make sure it works, something Psyphon takes well.
Outside the cave, Chromastone saves George from Diagon's laser by using his energy absorbing ability, and then shoots ultraviolet rays to Diagon, giving George an opening. However, when George fails to land a hit on Diagon, Chromastone fires again, yelling that he's out of energy. Gwen asks how much energy he can hold, and when answered "a lot", Gwen charges him up with mana, allowing Chromastone a larger blast. However, Diagon has become annoyed with the heroes' constant attempts to stop him and knocks Chromastone to the ground. George attempts to make another attack on Diagon, but however, Diagon sends a red bolt of lightning down from the sky that zaps George. Weakened, George reverts to his old man form, dropping Ascalon, and kneeling on the ground. He then turns completely grey and begins to blow away in the wind as dust. When Ben recovers, Gwen sadly informs him of George's demise.
Diagon relishes in his victory over George, proclaiming that his conquest of this dimension will soon come to fruition. However, Vilgax comes into view with Psyphon and the machine, declaring that if anyone is to rule this universe, it's going to be him; he also plots to take over Diagon's universe as well. Diagon then attacks Vilgax, planning on destroying his "weapon". However, his laser beams are absorbed into the machine as it keeps drawing in his power. Psyphon explains that under normal conditions, the device simply drains a being's powers. However, since Diagon's very being is made of power, he gets absorbed by the machine. Upon completely absorbing Diagon, Vilgax demands his power be given to him. Ben tries reasoning with Psyphon, but he doesn't listen. Upon gaining Diagon's powers, Vilgax takes a form similar to him and shoots laser beams at the team, leaving nothing but a smoldering crater where they were.
However, it is revealed Gwen teleported everyone to the Plumbers' Mount Rushmore base. Ben theories that they have a couple of days before Vilgax figures out they aren't dead and how to properly use his powers to find them. However, he is proven wrong the minute he stops talking as Vilgax's voice demands they come out and face him, sending the Esoterica to attack them. However, Gwen activates the base's defense system, warding off the mindless drones. Annoyed, Vilgax resumes his previous form and rips off the Washington face from the monument, disabling the defense system.
Once inside the mount Rushmore fort, Vilgax begins tearing apart the base, knocking out Gwen and Kevin. Faced with Ben in one final stand-off, Vilgax wonders what tricks will Ben use this time, only to see him grab the Ascalon and become covered in armor; Ben decided not to use the Ultimatrix, having figured out how to use the sword. Vilgax fires energy blasts at Ben, but he reflects them back at Vilgax with Ascalon. They both charge at each other, and in a flash of light, Vilgax is reverted to his normal form; Ben absorbed Diagon's power into Ascalon. When Vilgax questions what he'll do with Diagon's power, Ben tells him that he'll change the Esoterica back to normal.
However, Vilgax says that with the Ascalon, the Ultimatrix and Diagon's power, he could rid the universe of evil for good. Ben finds this interesting, but a recovered Gwen and Kevin question if he should actually take moral advice from Vilgax. Julie and Ship arrive, asking Ben to stop. Stressed with the choice with what to do, Ben asks for quiet as he remembers all of his adventures. Raising Ascalon, Ben sends beams of light all over Earth, turning everyone back to normal, just as he said. Julie kisses Ben, something he says is worth giving up all that power.
Pondering what to do with Ascalon, Ben is shocked to find Azmuth standing in front of him, demanding it back. Upon its return to Azmuth, Ascalon is sent into the stars. Azmuth then demands the Ultimatrix from Ben. Ben complies, confused as he thought he had proven himself worthy to use it. Azmuth points out that he still doesn't understand; an inferior copy of the Omnitrix is not worthy of him, leading Ben to question Azmuth again. Annoyed that Ben didn't let him finish, Azmuth tells Ben to look at his wrist, which now has a new Omnitrix. Further elaborating, Azmuth explains this is the Omnitrix, and that the previous one and the Ultimatrix were both prototypes he made while working on this one for the last six years. Ben then asks if he can have master control, leading Azmuth to playfully smile and reply "Perhaps for your 18th birthday."; then, Azmuth leaves. The episode ends with Ben, Gwen, Kevin, Julie and Ship together.
- Ben and Julie share their first kiss.
- Ultimate Way Big makes his first appearance.
- Sir George is killed by Diagon.
- Vilgax absorbs Diagon's powers.
- All of the Esoterica are turned back to normal.
- Azmuth removes the Ultimatrix from Ben so that he could give him the new Omnitrix.
- Max Tennyson
- Verdona Tennyson
- Manny Armstrong
- Helen Wheels
- Carl Tennyson
- Sandra Tennyson
- Young Ben
- Baby Celestialsapien
- Cash Murray
- Pierce's Girlfriend
- Aggregor's Soldiers
- Diagon (Later absorbed by Vilgax and then sealed within Ascalon)
- Vilgax (defeated)
- Flame Keepers' Circle (defeated)
- Esoterica (returned to normal)
- Jury Rigg
- Way Big
- Ultimate Way Big (first and only appearance in Ultimate Alien)
- Ultimate Wildmutt
- When we see the flashbacks through Ben's mind some of the footage contained scenes where Ben wasn't even present e.g Gwen restoring Darkstar in Absolute Power Part 2.
- When Ben transformed into Ultimate Wildmutt, he only had 3 "noses" instead of 4.
- When Ultimate Wildmutt was attacking the Esoterica, his lips were the same color as his skin.
- In one scene, after Ben transformed into Ultimate Wildmutt, Kevin's body was not covered in metal.
- In one scene, when after Vilgax destroyed the Plumber base, Gwen's helmet was gone.
- In the scene where Ben is in the midst of being tempted by Vilgax into using the power of the Ultimatrix, Ascalon, and Diagon to rid the universe of evil, Julie Yamamoto suddenly is able to help Gwen and Kevin talk him out of it, despite not being present when the conversation started. How she knew this happened is unknown.
- In one scene, Ultimate Way Big's hands are miscoloured.
- The title of this episode was also used for the Danny Phantom movie, The Ultimate Enemy.
- Vilgax mentions "tiresome Ultimate Forms". This is a nod to many fan's reactions towards the Ultimate Forms similar to when Ben reflects Sumo Slammers: Hero Generation to Alien Force and how it wasn't as good as the original.
- Ben's brief flashback shows us various events that happened throughout Alien Force and Ultimate Alien.
- This episode was dedicated to Dwayne McDuffie, one of the writers and story editors, who passed away in 2011.
- Azmuth reveals that the original Omnitrix and the Ultimatrix were prototypes.
- According to Derrick J Wyatt Azmuth deactivates the Ultimatrix some time after the events of this episode.