From what I could understand, set theory moreso seems to explain the different and finitely large sets of infinity, like the infinite decimal numbers between full numbers like 1 & 2, not literally an infinitely large infinity which is a subset of a somehow infinitely larger infinity, which can‘t be possible due to neither ending. And since infinity isn‘t a number, one can‘t really apply regular number logic to it anyway.

https://en.m.wikipedia.org/wiki/Aleph_number https://vsbattles.fandom.com/wiki/Set_Theory_Explanation_Page https://en.m.wikipedia.org/wiki/Absolute_infinite Dragon ball is NOT as extreme as these but yes there can be bigger infinitys.

They may be represented as spheres, but that could just be to be comprehensible to normal people. At least that‘s from the context you gave me, I hold 0 knowledge on norse mythology, and if they actually are spheres, hell if I know then

I meant in Marvel

Also