QUOTE
Nyx is the first-born Goddess. She was the first to form out of endless chaos. Some say that she is the daughter of Phanes, but I personally don't think so. Once formed, she gave birth to the world egg. The egg split into two pieces, the upper became the celestial realm, and the lower became Gaia. (The reason I don't believe Phanes was the father of Nyx is because he was born from the world-egg, and if Nyx birthed the world-egg, how could this be?)
The rhapsodies describing the orphic theogony refer to Nyx as the mother, daughter or wife (or daughter and wife) of Protogonus (Phanes). In texts that consider Nyx, as Protogonus (Phanes) daughter, the egg is formed from combination of Chronus and Aether (or Chronus and Chaos, or Chronus and both).
There are extracts from ancient texts referring to Nyx, collected in the following page:
NyxAlso, there are some references to Nyx, in Commentaries on Plato’s texts made by Neoplatonistic philosophers, Proclus Diadohus (412-485 AD) and Hermias the Alexandrian (5 AD), (although, the Plato’s texts, which they are commenting on, are not referring to Nyx).
So, in Proclus’ Commentary on the Plato's Timaeus, Zeus addressing Nyx says:
"Maia, supreme of Gods, Immortal Night, tell me this,
How shall I constitute the magnanimous first principles of the Immortals?"
"Surround all things with ineffable Ether, and place them
In the mid Heaven."
And
Hermeias in his “Commentary on Plato's Phaedrus” says that 'Orpheus, speaking of Night, tells us that "he [Phanes] gave her the mantic art that never fails, to have and hold in every way".
So, according to these philosophers, Nyx possess the highest art of divination.
Also, from this time period, Damascius’ “The Theogonies” is useful, as he makes a synopsis of a number of ancient theogonies in his text (some mentions Nyx and some not). It is interesting that Damascius in this text express the opinion that Homer constitutes Nyx his first principle and not Oceanus and Tethys, while this later happens to be the generally accepted opinion today.