Let me break it down for you so you can understand.
The writters said that he can destroy omniverse not a multiverse and isn't just Ben 10 multiverse but cartoon network multiverse you can't say that Marvel universeis bigger than CN multiverse
Please show me where it was ever stated that the the Cartoon Network Universe is connected to the Ben 10 universe. That is bullshit otherwise. On the other hand, all of Marvel's publications are considered interlinked as separate alternate realities in a larger continuum.
Also that is a statement from a writer not a fictional chracters and in the episode " Ben again " Eon via Paradox's power source was going to destroy the multiverse and the Celestialsapien are more powerful than Paradox
That had nothing to do with sheer power. Eon was destroying the world because he was breaking the time stream. The same thing happened when Kang the Conqueror fought Ultron. I guess going by your logic, Ultron and Kang are multiversal+ beings.
Dwayne MCduffie and many other writers said Alien X is omnipotent its a fact
Stan Lee has also stated the same for Galactus. He stated so in the Fantastic Four comics that he authored and in a recent Twitter question:
I find this entire dialogue pretty ironic considering that you completely invalidate your own argument. You claim that Alien X is omnipotent, but says he requires six thoughts to actually destroy the Ben 10 omniverse. That by it's own volition is contradictory to what is claimed.
Since I don't want to discuss this point any longer, this will be my last point on the matter.