Alien X

Alien X is the Omnitrix's DNA sample of a Celestialsapien. Alien X's three personalities are Bellicus (Anger), Serena (Love), and Ben Tennyson (Reason).

Theories
The following theories have been made to explain Alien X's creation and existence, which seems to come into conflict with that of other Celestialsapiens:
 * 1) 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.
 * 2) Normal Celestialsapiens don't really have a voice of reason, Alien X has one due to Ben and the Omnitrix.
 * 3) Alien X is 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.
 * 4) Since most species only have one voice, that the Omnitrix is designed to replace the mind of an alien with the user's mind, and is not capable to replace more than one voice.

History
Despite Alien X's power, Ben rarely uses his Celestialsapien form, due to the headache of having to deal with Bellicus and Serena. This problem has recently been resolved, due to the agreement that Ben takes full control over Alien X; Bellicus and Serena focus solely on their debates.