Theory about the definitive Omnitrix:

I believe that when the watch collects a DNA sample from some sentient being it removes some things from the genetic code that are the characteristics define the appearance of the donor and leave the most important that are the powers and abilities and the parts have been removed are replaced by the user’s this explains why Whampire is different from Lord Transyl and this is similar to those Sha Figuarts action figures from Bandai