But epsilon-null, a set of ordinal numbers that has a stupid amount of powers of omega, still has the simple cardinality of aleph-null. What is the difference?
The fact that omega still increases by addition?
I mean we use the axiom of replacement to prove power sets so how about we look at one that proves ω1.
So replacing each ordinals on the well ordered set of omega will result to ω1
(
ω1=) so this itselfs prove that ordinals can increase by addition albeit with axioms.
Now lets go above the ordinals we know and go to a realm where bijections becomes rare.
So with this it's quite adequate that ordinals can indeed go high in rankings and is additional proof that it can increase by addition as you can use the axiom of replacement to prove higher rankings above Vω+ω and below.
(axiom of replacement mostly rely and uses ordinals.)
We also have Vβ+1 which is a great example that larger ordinal models can't be bijective even by additions since Vβ+1 is a power set of Vβ.
This also shows that some ordinals can imply a reinhardt cardinal.
We should also consider the fact that a δ that satisfies a berkeley cardinal is still a ordinal none the less as it still uses the ordinal δ to represent/denote itself.
Ordinals and order theory (with transfinite induction) in general proves that there are initial segments and induction marks which then proves there are bijections, other existing sets, bigger sets that precede smaller ones and etc.
Conclusion:
Overall while some cardinals are denoted by ordinals and while the 1st order ordinals uses different mapping methods compared to cardinals, each cardinals still has an ordered pair and in fact (from what I know) each cardinal is a ordinal but not vice versa.
Also to simply put most (if not all) of the representing symbols we see in large cardinals are ordinals.