A Question about Gilgamesh splitting heaven from earth

[Lunacorva]

So just yesterday, I was talking to someone about the Fate series. And he brought up the fact that Gilgamesh once split heaven from earth with a single attack. and since that's basically severing two dimensions from each other, then he and the other Heroic spirits should be considered "Reality Breakers" instead of just "Worldbreakers"

Now, I have no familiarity with the Nasuverse, so I wanted to ask you guys. is there validity to this claim? Would seperating two dimensions be a low 2-C feat or even higher? Has there been other "Reality breaking" feats in the Fate series?