The nymphs are possibly inspired from Dante manuscripts

[ololololo]

There is no cipher that is even remotely as hard to crack as a language which is not related to any language you know.

What's the probability that the VMS text is a completely unknown, never before encountered, European natural human language? I would say close to 0.

Right. But that’s not what Jorge meant (as I understand). Decoding the language is much more difficult than deciphering a cipher.
Moreover, even if we know the language but not the writing system, the task does not become any easier. Example: rongo-rongo (if this is a language, then most likely Rapa Nui. What does this give us?)