Yes relativity exists. Yes soccer is football in England, Happy? But this kind of relativism is mostly semantic.
Are you saying that Catie and Boxxy are the same person, because someone else has categorically denied that,
Either Boxxy does not exist, or Boxxy and Catie are the same person If two people disagree, I have to think they'e disagreeing aboput semantics, about the precise meaning of "exist" and "person", and maybe even "Catie" and "Boxxy", but the underlying reality is straightforward and generally agreed on. The facts exist, and they are facts, even if you can't agree on how to express them. We can disagree about the identity of Jack the ripper, yet Jack the Ripper was someone. There is a right answer, even if no one knows what it is.
Relativism exists, sure, but it doesn't apply in all places equally.