Q: Is destroying multiple infinite multiverses a better feat than destroying a single one?
A: In spite of what our intuitions may tell us, destroying or fully affecting multiple infinite-sized multiverses is in fact not better than doing the same to a single infinite multiverse, and thus, not above the "baseline" for 2-A
The reason is that the total amount of universes contained in a collection of multiple infinitely-sized multiverses (even one consisting of infinitely many of them) is in fact equal to the amount of universes contained in a single one of the multiverses that form this ensemble: It is countably infinite, as the union of countably-many countable sets is itself countable, and thus does not differ in size from its components. The only general difference between multiple infinitely-sized multiverses and a single one is representation. What is considered to be multiple multiverses in one fiction could be considered a single multiverse in another, and vice versa, without the objective properties of those collections of universes changing. The only difference is where an author decided to draw the line between what belongs to the same multiverse and not. Thus, only an uncountably infinite number of universes actually makes any difference in terms of Attack Potency, at this scale.
This illustrates some of the more unintuitive properties of sets with infinite elements: Namely, given a set X, it being a subset of another set Y does not imply that Y > X in terms of size. An example of this is how the set of all natural numbers contains both the odd numbers and even numbers, yet all of these sets in fact have the same number of elements.
Similar to Attack Potency, affecting multiple multiverses by default can not be considered a feat of superior Range to affecting a single one. As mentioned before there is no real difference between the size or properties of one or multiple multiverses. Hence there can be no objective difference in range either. This is made even worse by the fact that what we considered multiversal range, as the distance between universes or the distances between things in or between multiverses, is usually not directly stated or quantifiable in fiction, but instead is approximated by the number of universes. That idea becomes meaningless if we try to quantify different ranges within sets of universes of equal numbers. As a consequence, even if one verse gave an indirect indicator of different ranges in its multiverse it would be impossible to compare to a different fiction where such a quantification doesn't exist.
For example, if travelling to another multiverse is said to take longer than travelling within the same one, that would seem to be an indication of different ranges, but at the same time one can not compare those informations to another fiction, as there is no way to tell how travelling within the same multiverse in another fiction compares range wise to either of those distances.
However, feats regarding affecting multiple multiverses may indeed qualify as higher range if the verse itself treats it as such. Those feats need to be relatively explicit and objective. For example, one multiverse being outside of the range of an effect or of the power of a character that can affect one infinite multiverse doesn't necessarily mean the multiverse is further away. Other factors such as differences in nature and domain of the multiverses or characters could, amongst other many other factors, also be the reason.
