Order, Evolution, and Infinity.
Soul, Paradox, and Chaos.
I was thinking about the hierarchy of God > Outer Twins > Arbiters > Apostles, and I've been trying to see how the two sets of Arbiters work together. So Order, Evolution and Infinity feel like properties of the world as it currently exists, if that makes sense. If you interpret Order as being the laws of physics, evolution being change, and infinity as describing the dimensions of reality, then we could say that the first Outer Twin embodies properties of the universe as it currently exists.
The second arbiter sort of feels like things that necessarily exist outside of reality. Paradox, representing incompatible states of being, Chaos representing the primordial nothingness before creation and after heat death, and I guess technically Soul counts? We've never actually seen any confirmation that an afterlife exists, so perhaps it doesn't? All we know is that a part of you can persist within the memory world, but this isn't meant as a proper afterlife since it decays the longer it stays there. So I suppose Souls intend to fade away into nothingness after death.
So perhaps we're looking at Is vs Is Not, or Something vs Nothing, or Existence vs Nonexistence.
Granted, these don't fit as neatly together as the arbiters did for the apostles, but there might be something there. Or we could be off base with our assumptions of the cosmic hierarchy, which is also possible but I find it less than likely, if only because of the strong correlations between the Apostles, Arbiters and God. Given separating into smaller more specialized demigods seems to be a pattern, the idea of the Outer Twins being an in-between step between God and the Arbiters makes a lot of sense imo.