I have heard the term Avitchi Nirvana referenced by Master Koot Hoomi in theosophical literature, but have never encountered the term in any Gnostic literature. What is it? Is it the 9th sphere of Klipoth? Something else?
Is this the quote by K.H. that you are referring to?
After the completion of the great cycle [there is] either a long Nirvana of Bliss (unconscious though it be in the, and according to, your crude conceptions); after which — life as a Dhyan Chohan for a whole Manvantara, or else "Avitchi Nirvana" and a Manvantara of misery and Horror as a —— you must not hear the word nor I — pronounce or write it. But "those" have nought to do with the mortals who pass through the seven spheres. The collective Karma of a future Planetary is as lovely as the collective Karma of a —— is terrible. Enough. I have said too much already.
He seems to be stating that after the Manvantara (Cosmic Day), there is a period of Nirvana—“cessation.” We refer to this as the Cosmic Night, the Pralaya, in which activity ceases. During this period, one may experience a period of bliss or a period of hell, Avitchi, according to K.H.
"If thou canst not make thine own self what thou desireth, how shalt thou be able to fashion another to thine own liking. We are ready to see others made perfect, and yet we do not amend our own shortcomings."
—Thomas à Kempis