Alien X

Alien X is a Celestialsapien who was born in the Forge of Creation. He is an Omnitrix alien that appears in the show Ben 10: Alien Force and Ben 10: Ultimate Alien.

Ben first transformed into Alien X during the episode X = Ben + 2 when fixing a dam broken by Sevenseven while trying to shoot Attea.

Biography
Ben acknowledges Alien X as his most powerful alien; however, he cannot afford the cost that comes with becoming the alien. Alien X is a being capable of warping reality at will. He has a black body covered with tiny white stars, white hands, green eyes, and three horns protruding from his head. He has three distinct personalities: Serena, the voice of love and compassion; Bellicus, the voice of rage and aggression; and Ben, the voice of reason. All three speak in unison when Alien X speaks. In order for Alien X to perform any action, including but not limited to, simple movement and transforming back into Ben, two of the three personalities must agree to do so. As both Serena and Bellicus have been arguing for an eternity, and before they had no tiebreaker, getting them to focus on any present task is difficult at best, leaving the body of Alien X frozen in place while Ben attempts to convince them to act.

Alien Force
Alien X first appears in X = Ben + 2, where Ben uses the form to stop a flood caused by a broken dam. After much fruitless argument, Ben eventually convinces Serena and Bellicus to transform him into one of his other nine aliens. He swears off using the form afterward, as it is not worth the price the power comes at.

Alien X is mentioned in Darkstar Rising, where Kevin suggests to use Alien X against Darkstar. Ben declines as there would be no stopping him if he had absorbed Alien X.

Ultimate Alien
Alien X appeared in the episode "The Forge Of Creation" to stop Aggregor from going to the forge of creation. Except Bellicus and Serena keep debating about other things. Suddenly Paradox appears, telling Ben that he would not be able to convince Belicus and Serena to help him out today. Also, Paradox puts himself in danger by going into the presence of Bellicus and Serena who almost voted to destroy him, and changes, Ben and himself back into his human form before they voted.thumb|300px|left|Alien X Transformation

Weaknesses
In order for Alien X to perform any action, including but not limited to, simple movement and transforming back into Ben, at least two of the three personalities (Serena, Bellicus, or Ben) must agree to do so. This reveals to be a major weakness, as the personalities initially weren't even interested in dealing with present affairs and wanted to finish some past ones that weren't possible to deal with and without Ben (with a comical scene where Bellicus reopens a discussion on whether or not to save the dinosaurs from extinction).

Alien Force

 * X = Ben + 2

Zac 10 Ultimate hero

 * The osmisian's revenge(First reappearence)
 * The trap(2x)
 * Go ultimate(selected alien was Generator 10)
 * Power surge(selected alien was Wildmutt)

Video Games

 * Ben 10 Alien Force: Vilgax Attacks

Alien Force

 * 4" Alien X
 * Alien X (Planetary Powder)
 * Alien X (Alien Creatures set)
 * 10 cm Alien X (DNA Alien)
 * Alien X with Goop (Black version) (Creation Transporter)
 * Alien X (Defender) with Alien Bust
 * Alien X (Alien Creation Launchers)
 * Omnitrix Hero Collection with Alien X hologram
 * Alien X (Alien Rocks)
 * Alien X (Keychain)

Ultimate Alien
Alien Creation Alien X and Ben

Ben 10 Alien Force: Vilgax Attacks
Alien X appeared in the game (only in the CGI movies/clips for X-Box 360, Wii, PS2 and PSP). He is not a playable alien being replaced by Cannonbolt/Upchuck.

Trivia

 * He has only been used twice, in X = Ben + 2, and The Forge of Creation making him the second least used alien (tied with Benmummy used once in The Return and Ken 10) beating Benvicktor and Benwolf which have only been used once.
 * Dwayne McDuffie confirmed that he's not the most powerful being in the Omnitrix/Ultimatrix. This can be seen here
 * Alien X has a white shadow.
 * Alien X also cannot be destroyed if all voices agree.
 * The extent of his power is unknown, although Paradox stated that if Aggregor absorbed a baby Celestialsapien, he would become omnipotent.
 * Before he appeared, the opening showed only a shadow of him, after he did it showed a normal image.
 * The X in his name is probably used to signify him being the 10th alien by the Roman Numeral 10. It may also relate to his mysterious nature, as X is often used in Mathematics to represent an unknown number.
 * At the beginning of the video game Vilgax Attacks, Ben starts to turn into Alien X. But Paradox tells him not to yet, but later in the game there is a cutscene where he sends Vilgax and Psyphon to the Null Void. In the DS version, after being defeated by Ben, Albedo turns into Alien X but is frozen and cannot do anything. After the credits in the last level, we see a cutscene where Albedo is still frozen in Alien X.


 * He is also becoming a "Nano" and a NPC in Cartoon Network Universe: Fusion Fall.
 * Bellicus's name is probably based on the word bellicose, meaning aggressive or eager to fight, while Serena's name is probably based off the word serene, meaning calm or peaceful, both references to their personalities.
 * Alien X appears to be made up of space itself, hence the stars all over his body and how Paradox was able to teleport inside him.
 * Alien X is one of the five alien forms that shares the same voice actor as its human form. The other four being Upgrade, Benwolf, Buzzshock, and AmpFibian (only in episode Fused).


 * Alien X is one of the nine aliens to appear on a limited edition smoothy cups in Andreas’ Fault.
 * Alien X is Ben's 30th alien, and it's the 10th alien of Ben 10: Alien Force.
 * Through Alien Force, Kevin tries to get Ben to use Alien X even though he knows all about the risks of using him.
 * In Andreas’ Fault, a devoted fan of Ben's refers the "Alien X" smoothie as a disappointment as well as calling it "filler". This is an obvious reference to Alien X's standing in the series.
 * The three horns on Alien X's head could represent the three personalities that control Alien X.
 * Alien X is so far the only alien with 5 fingers.
 * In X = Ben + 2 Ben did an action first then had to argue. But in The Forge of Creation he didn't do anything to start the arguing
 * Ben had Kevin rig the Ultimatrix with an extra lock, preventing anyone from accessing Alien X without first inserting two keys. This was done to prevent people with bad intentions like Albedo from using Alien X and to keep Ben from being transformed into it by accident and possibly prevent those who could absorb powers from stealing its power or/and its energy.
 * The block set on the Ultimatrix that prevents the use of Alien X appeared to have been reactivated after Professor Paradox transformed Alien X back to Ben, for when Kevin absorbs the powers of the Ultimatrix later in the episode to save their lives, he did not receive the abilities of Alien X..
 * Alien X is the second Alien Force alien to be shown as a baby, the first being Big Chill.
 * In The Forge of Creation, Paradox somehow turns Alien X back into Ben.
 * Only Bandai revealed the planet Zvezda, but Dwayne McDuffie has said it doesn't exist and should not be considered canon to the animated series and is revealed in Ben 10: Ultimate Alien that Celestialsapiens come from the forge of Creation, a location outside of the universe.
 * Because of this, Alien X is Ben's only alien in the Ultimatrix (and probably the entire codon stream) to not live in our universe.
 * It has been confirmed by Dwayne McDuffie that a baby Alien X does not have multiple personalities.
 * Professor Paradox has hinted that Ben will one day use Alien X successfully.
 * It is unknown how the DNA for Alien X was collected since Azmuth does not have access to The Forge of Creation. It could be that Professor Paradox collected the DNA for Azmuth and could explain why Paradox is no longer allowed within 500 light years of them, because he could have collected the DNA without their consent (it would take a very long time for them to decide even if he did ask).
 * According to Dwayne McDuffie Celestialsapiens also live in the Milky Way, but they're born in the Forge.
 * Before the events of X = Ben + 2, the opening sequence of Alien Force showed Alien X as a silhouette. But after that season, they actually show Alien X's true form instead of his black silhouette.
 * It is unknown how Ben's association with Paradox affects Ben's relationship with Bellicus and Serena, since Ben is the voice of reason in Alien X and Paradox is not supposed to be within 500 light years of any Celestialsapien.