Superman still speed blitzes Ben before he even thinks about pulling the ''multiplication'' stunt or anything, really. Superman would have to literaly sit down and wait at least a minute as Ben does it. There are only one or two aliens that cant get speed-blitzed (And thats being generous), even if Supes decides to wait for him to transform.
And Ben 10 Omniverse is really mediocre, even ignoring the art style. The older series was way better....the serious tone was perfectly done and actually made Ben likeable (I just cant watch the original series at this point....he was way too much of a prick).
Heck, in Omniverse, the plumbers are even more incompetent than usual....the animal dude (Forgot his english name) literaly escaped his cell and had a super laboratory with thousands of mutant aliens RIGHT BELOW THE DAMN BASE and NOBODY EVER REALISED IT. Heck, when Ben went to ''visit'' him (There were plenty of plumbers there), Animal was not even there and nobody noticed a damn thing. That sort of plot hole just hurts my head. In the past, the plumbers were fodder, which is perfectly fine....now they are just moronic fodder.