Celestialsapien

Celestialsapien (A play on "celestial," meaning from the stars, and "sapient," a term for intelligent) is the species of Alien X from Forge of Creation

Appearance
Celestialsapiens are fairly simple in physical design. They are silhouette-like humanoids that can range from any size. They have white star-like dots scattered inside their body and three trident-like horns on their forehead. Their face only consists of pupil-less eyes.

Personality
They prefer their shrouded existence in The Forge of Creation, as opposed to being involved with the "petty going-ons" of the rest of the universe. Celestialsapiens have three personalities: the voice of rage and aggression, the voice of love and compassion, and a voice of reason. Two out of three must agree on something in order for the Celestialsapien to perform any sort of action. All three voices speak in unison when the Celestialsapien speaks, and depending on what the voices agree on, they shout either "Seconded!",or "Motion carried!" if they agree.

Dwayne McDuffie Confirmed that Baby Celestialsapiens don't have multiple personalities.

Powers and Abilities
Celestialsapiens have a strong ability to warp reality, meaning their thoughts can come to life, on a scale sufficient to recreate the universe itself. They apparently are able to alter time, space, and dimensions. Their reality warping is so powerful, that the personalities can even prevent the Celestialsapien from being destroyed just by agreeing that it won't.

Alien X
The Omnitrix's DNA sample of Celestialsapien is Alien X. A theory is when Azmuth took the Celestialsapien's DNA, he used his advanced technology to remove the voice of reason, so that it could be replaced by the wearer of the Omnitrix when they transform into Alien X. Another theory is that normal Celestialsapiens don't really have a voice of reason, Alien X has one due to Ben and the Omnitrix. It is also possible that Alien X was unique in the fact that they did not have a voice of reason, which is why they allowed Azmuth to take a sample of their DNA so that whoever used it would become their voice of reason. Another possibility is, since most species only has one voice, that the Omnitrix is designed to replace the mind of any alien with the users mind, and is not capable to replace more than one voice.