Where do you get that from ?
We have no suggestion of constraints applying to a post-Darkhallow ascended.
Which I think is what makes the darkhallow so scary. Usually things with that kind of power have to work in the rules. They can, but aren't allowed to just rewrite reality on a whim (like jim said is theoretically possible to a mortal with enough umph and hootzpa). Whereas a sufficiently powerful (from pure juice) mortal wouldn't suffer from this handicap.
Think about what even a comparitively nice person like marcone (he's not all bad as shown by his fierce protection of children, even when its against his business interests. And he does try to keep the violence down so he's not a psychopath.) would end up doing with that kind of juice.
power corrupts. absolute power corrupts absolutely.