Ultimate Alien Ben wins. And it isn't just because it's a better show (which it is). The alien that Omniverse Ben uses the MOST is freaking Ball Weevil, now the one UA Ben used the most was either Swampfire or Humongasaur. Those two stomps Ball Weevil. Therefore UA Ben wins.
UA Ben turns into Way Big, then evolves into Ultimate Way Big an' then wildy starts poundin' Omniverse Ben like a gorilla, an' no matter what alien he picks there aint gonna be nothin' left of him after the poundin'.
Omniverse Ben is still only 16. Ultimate Ben is decades older and would obviously be more experienced and has unlocked far more aliens(over 10,000). He is also trained in H2H and can use a little magic. He has mastered the watch to such a degree that he could probably force shut down young Ben's Omnitrix.
This is another odd one to me in terms of how Kuro ranked him. Hax aside, Whampire is still a pretty decent fighter being capable of fighting a small number of aliens all by himself. His strength alone makes him superhuman, granted probably not as strong as a traditional vampire.
Ripjaws was like my second favorite alien when I was a kid since he reminded me of a mermaid when he was underwater. A mermaid leaning less on the beauty side and more on the terrifying side, but whatever! He can swim very fast and his jaws are strong enough to rip through pretty much any form of metal.
Yes dude, HAX does make Dr Who stronger than green lantern. In a fight, nobody cares whether someone uses hax or not, because ben uses it all the time. Hell, Doctor strange is on par with a regular human and he was able to hold against thanos with 4 infinity gems why? Because of hax. This list is far better than kuros but hax should be taken into account. Like toeepick can literally scare all of bens top aliens bar atomix into white oblivion.
we have barely explored the potential of any of the aliens.
So if an alien has telekinesis, can said alien move entire planets with these powers?
can ben turn into a billion dittos, then turn into a billion clockworks, and shoot their time rays at the earth, causing it to age to dust. Also, Feedback did not singlehandedly hold the big-bang. The Omnitrix turned Ben into every alien, (including Alien X) to overpower it, and then let feedback hold it.