Desire-Thought-Function. The creation of one enables the latter, ad-infinitum. From the first to the last and from the last back to the first.
This is depicted in the image above showing the minds many, many ways and ability to manifest this process in its countless permutations, all of them without the slightest flaw, or mercy, prolonging the presence of Samsara and not Nirvana in the mind´s own reality, the Dharmakaya.
Hence where there is Dharmakaya, the mind sees and experiences Samsara in its countless illusory forms.
This is the destiny of most sentient minds, from the lowest devil to the highest deva.
What their innermost self identifies with, becomes their nature. Most sentient minds cannot understand, nor realize what this really means because in their core mind, they have buried this to such depths and such low priority, it never surfaces to make them face the real truth about themselves.
For the demons, rakshasas it is the fear and hunger, for the asuras it is anger and hate that preoccupies their mind in their extreme realms of suffering, for the gods, it is the arousing and bewitching ability to create images of their own innermost desires as a reverence and affirmation of what they think is their ultimate self. For the humanized races and similar, it is a short-lived vibrating continuum, between energy and matter, caught in between these extreme entrapments of Spirit.
Consequently, they have and will have to endure, eons upon eons of painful rebirths (the absence of Nirvana) until this fact becomes like an awakening lightning of truth that changes their ways towards true self-realization.
This continuous process of misdirected self-identification and formation of a karmic body upon the next thought moment is instantaneous for any given spatiotemporal direction. It is like showing a sequence of images to a child in rapid motion, and soon the child believes the things in the displayed screen to have a life of their own as they seem to move around.
True Self-identification with the Unborn Mind is an instantaneous realization and a gradual acclimatization where there is nothing beyond this truth that is real. It is, if still present in the student’s mind, only illusion and is thus the foremost duty and goal of any genuine dharma student to fully realize by desiring nothing but the ever present grace and Noble Wisdom of the Unborn Mind.
For this to happen, the student should, throughout his time in this in-between realm of no extreme conditions, during its dhyana sessions disembody itself from any mind-formations, be it memories of past or desires of future, or a material body of what seems to be a present. if there is the notion of breathing, then the student’s mind is still bound to a body of birth and death. If there is the notion of heart beats, coldness or warmth, then the student is still subject to birth and death and so on.
This annihilation of all skandhic formation will at the end manage to one day smash the body-consciousness (fifth skandha) that is the last barrier between darkness and light, or self-ignorance and true self-realization of one´s Buddha Nature. What emerges then, has no name and cannot be said to be this or that that belongs to any father or mother or source of creation.
There are no short cuts to this goal other than a clear breakthrough of any and all obstacles of one´s own creation.