Primordials

As far as anyone is aware, primordials cannot die. They have always existed and It's likely that they always will. They are more or less conciousnes bound to universal concepts. Until you destroy entropy, you cannot kill Ptarraeug. There are three primordial that have ever existed in the observable universe. In the Spider Web constellation resides Nikta, in the Vortex constellation resides, and in the Mysts resides the green mother.

The Green Mother
Her Domain is Life and she created The realms between the mysts.

Ptarraeug
Their domain is Entropy

Nikta
Their domain Is Fate