According to Yungdrung Bön nothing is stable, permanent or final in samsara and so the cycle of life and death is explained through the teachings on the Bardo intermediate states. These are:
Bardo of Natural Abiding - what we call life;
Bardo of Dream - dream state;
Bardo of Samadhi (Contemplation) - state of meditation;
Bardo of the Time of Death - period starting at the beginning of a fatal disease and ending in death;
Bardo of Primordial Dharmakaya - period of returning to the fundamental ground of being, the Nature of Mind;
Bardo of the Clear Light of Emptiness - threshold between samsara and nirvana where lights and rays appear from the Nature of Mind;
Bardo of Taking Rebirth - the intermediate state between life and death before taking rebirth in one of the Six Realms of samsara.
The post-mortem fate of any being, not only humans, depends on karma which pushes the spirit to reincarnate in the body of one of the beings of the Six Realms of samsara and one lives out that life until the next death when the process is repeated again until one day, due to meritorious karma and tireless practice, one gains the realization of a Buddha. In very simplistic terms, in the case of human beings, the post-mortem fate largely depends on our actions in this life. Generally, if one led a good and virtuous life then one's post-mortem destination is likely to be a happy one in one of the three Upper Realms as a god, demi-god or human. If one's acts were evil then one will have a miserable rebirth in one of the three Lower Realms as an animal, hungry-ghost or hell-dweller. Although this seems a simple model, it is actually quite complex. The birth in any of the Six Realms depends on the accumulation of causes related to negative emotions such as envy, greed, jealousy, hatred, anger, mental torpor and pride. These are collected by any given being throughout countless lives. All beings, and humans in particular have amassed many negative causes which manifest as obstacles and sufferings in life and also affect the post-mortem destiny. All humans are always conditioned by thoughts and emotions; one moment there is a bad intention and thoughts conditioned by a negative emotion, the next moment there may come good intentions arising from virtuous thoughts. In actual fact, then, there are almost no absolutely 'good' or only 'bad' people so we can only speak of people who are more positive than negative or vice versa. Humans, however, have an advantage over other beings of the Six Realms, namely, enough intelligence and the necessary circumstances to understand the causes of suffering brought by continuously wandering in samsara. This means that - at least theoretically - humans are able to enter the spiritual path laid out by the Buddhas through which one can go beyond dualism and suffering, and help others to do the same. So the after-death experiences and fate of ordinary people, be they good or bad, is entirely different from those of realized practitioners of Yungdrung Bön and other forms of Buddhism.
Death is the separation of the mind from the physical body composed of the five elements. What dies is the physical body; mind cannot die because it is immaterial. As the elements dissolve into each other, an ordinary dying person experiences a series of overwhelming visions and sensations which they perceive as coming from outside. These experiences bring great suffering and fear. For example, when the earth element starts to melt into the water element one feels as though crushed by a heavy mountain. Coupled with attachment to friends, relatives, unfinished tasks, possessions and the whole situation of life in general, this makes them suffer greatly. It is very important to try to relax at this stage, to let go of grasping and emotions as strong negative emotions at this juncture are tremendously powerful and will push one towards an unfortunate rebirth. Violent death brings other dangers. Through inverse attachment and desire for revenge, the spirit of a murdered person, for example, may become a dangerous ghost harking back after its murderer(s) and turning against the living in general. Similar things may happen to the spirits of the victims of an accident.
The situation is quite different for an experienced practitioner who practised Buddha's teaching and trained his/her mind in the realization of the illusory nature of all phenomena. When the visions and experiences related to the separation of body and mind appear, such a practitioner knows the order and characteristics of this process and realizes that all these visions and sensations are not something external but are manifestations of his/her own mind. The power of such person's practice alleviates the sufferings of death. Whether one suffers at this stage or not depends, of course, on how much and how thoroughly one has practised during the lifetime and how strong one's meditative stability is. For example, Dzogchen practitioners of the highest capacity do not enter the death process at all. Extraordinary practitioners such as Tsewang Rigdzin or Guru Padmasambhava dissolve their physical body into the essence of the elements while still alive, manifesting the Rainbow Body which is immaterial. The process is invisible to others who continue seeing them as if they had a normal physical body. This highest realization is known as Phowa Chenpo, the Great Transfer. Such masters can reappear and disappear at will and give teachings to students with the necessary qualification in any time and place. Other Dzogchen masters of high capacity enter the final meditation at the end of their life. This lasts approximately a week. In the process of this final meditation session the Dzogchenpa's body dissolves into the essence of the elements and only some hair and nails are left behind. Rainbow Body is the most active form of a Buddha and can directly help sentient beings who have devotion and karmic connection to this particular Buddha. Lesser practitioners of Dzogchen rely on Phowa methods by which the consciousness is transferred thereby avoiding the sufferings of dying altogether and instantaneously arriving at the final realization of the Natural State of Mind thus becoming a fully realized Buddha. Many Phowa transference methods belong to different levels of Tantra, too. In the case of Higher Tantra, for example, a yogi transfers their mind into a form of the yidam deity, a Buddha-form they have familiarized themselves with all their life through meditation and dream yoga, and attains the realization of the Illusory Body. On lower levels of Tantra a practitioner's consciousness is transferred directly into the paradise of Ogmin, for example, where one can continue practising without obstacles until achieving final realization. In short, there are very many methods in Yungdrung Bön, and in Buddhism in general, which bypass the sufferings of dying and instantly deliver the practitioner's consciousness to one of various levels of spiritual realization.
All those who have to go through the process of dying finally arrive at the Bardo of Primordial Dharmakaya. Here, too, a practitioner's experiences differ greatly from those of ordinary beings. Ordinary people experience this period as a blackout, unconsciousness, which can last from just a few seconds to up to three days. Sutra teachings also generally view it as an unconscious state. For an advanced practitioner of Dzogchen or Higher Tantra, on the other hand, this period presents chance to gain full liberation because they have trained all their life to recognize this state, the fundamental nature of their mind, through the practices of contemplation and dream yoga. Now, when their mind arrives at this Bardo, it remains inseparable from this primordial state and the practitioner gains liberation from samsara.
Dream practice in Dzogchen and Higher Tantra is based on the knowledge that the process of falling asleep - when the mind turns its grasping attention from external objects and situations to the bagchag, karmic traces stored in the Kunzhi Namshe or Basic Storing Consciousness is similar to the process of dying. When we fall asleep, the mental consciousness roams through the random mixture of memories and tensions accumulated during countless lifetimes and stored in the Kunzhi Namshe and we see these karmic traces as dreams. In the case of dying, these visions are the visions of the Bardo of Taking Rebirth. But in both cases, before the internal visions appear to the mind, the mind dissolves for some time, no matter how short, into its base, the Nature of Mind which is also called the Nature of Phenomena. Dzogchen and Higher Tantra have different methods of dream yoga. While in Dzogchen a practitioner tries not to lose but to maintain continuous awareness of the Natural State while sleeping and dreaming, Tantric yogis use dreams to train in transformation into the yidams in order to be able to manifest as a yidam when they die- the realization of Illusory Body.
After the Bardo of Primordial Dharmakaya one 'wakes up' in the Bardo of the Clear Light of Emptiness. This Bardo is said to have a general duration of three days and four nights. Here lights and rays start manifesting from the primordial ground. Advanced practitioners recognize these lights and rays as the display of their own Nature of Mind and thus gain liberation. Ordinary beings perceive and grasp the lights and rays as the external objects, follow after them so the lights and rays solidify and turn into the visions of the Bardo of Taking Rebirth. These Bardos pose many challenges and has many potential sufferings. Firstly, one may not realize that one is dead. This is especially true for people who died in an accident or in some other violent way. After a period of blackout in the Bardo of Primordial Dharmakaya the senses 'wake up' and continue to function. The power of attachment drags the deceased towards relatives, friends, enemies, places where one used to live and so forth. The mental body, the spirit of the dead person is immaterial, so it can go right through material objects and people and travel in an instant to any place just by 'thinking' of it. The deceased may try to talk to relatives and friends but they cannot hear him/her so they feel rejected and alone. The spirit can become very upset, frightened and confused seeing its former body burnt, buried or destroyed in another way. On top of that, although one has left the physical body behind, due to attachment and grasping one may still feel hot or cold, desire food, clothing and other objects and suffer greatly because one cannot get them. The Surchö rituals in Yungdrung Bön alleviate these sufferings. Another danger at this time is presented by the Shed spirits who try to take possession of the deceased's la and enslave him/her. This kind of problem is cut off by the Shedur rites performed in the first three days following a person's death, or as soon as possible if the death was violent. Through these rites the la of the deceased is reunited with yi and sem, and propelled towards the next rebirth while the relatives are liberated from the demonic appearances of Shed.
In the Bardo of Taking Rebirth, experiences of different beings vary considerably:
The condition in the Bardo is just the same as this condition in dreams. We have feelings and (see) everything perfectly, but nothing is stable; things are always moving and no matter what comes into this being’s thinking, he cannot stop it. [...]
When these kinds of spirits are in the Bardo time, they are like flies or insects in summer - when flies see some meat, too many of them come and swarm around it. In a similar way, too many Bardo-beings swarm around when a couple is uniting. But it is not easy for the Bardo-beings to be connected with the couple; it is important to have a previous karmic cause with them. Otherwise, the Bardo-beings can see the couple but it is not easy to integrate with them. How they integrate depends on previous karmic cause, whether it was good, bad or neutral; there are many ways. If the Bardo-being was a practitioner or a religious person in their previous life, then (when a couple unites) they may see a flower garden or a beautiful place or a palace and so they go there and have a rest. But after they have rested, they are stuck there like an insect which has walked in some glue. That means they have united with this couple (conception), and are beginning to take the next life.
(The experience of conception) very much depends on karmic cause. Even for normal beings which were not connected with good things, with religion or virtues or merits in their previous life, which were just ordinary, there are different capacities. Some are chased (in Bardo). They have enemies behind them and so they run away. In some cases they try to hide in a cave, and that is how they take birth in the Lower Realms. Once they have hidden, they can't move any more, just like an insect caught in glue. So that is another way."
In the first part of this Bardo one's feelings and visions are more related to the form and circumstances of one's previous life. In the second part of this Bardo one's feelings and visions change and are related to the form and circumstances of the next life. For example, a human first sees him/herself as human and has visions and experiences related to human existence. If that human is to be reborn as a cat then in the second part of this Bardo their experiences and feelings change to that of a cat. In the same way a cat may initially feel like a cat but if it is to be reborn as a human, in the second part of this Bardo it begins to feel and see itself as a human. If a person was a practitioner or at least received some teachings, they will have visions of various peaceful and wrathful Buddha-forms. If they recognize them as self-manifestations of their own mind and not as external forms, then their mind is liberated into these visions and they become a Sambhogakaya Buddha. In order to help the mind of the deceased through the stages of this Bardo there are several purification methods in Yungdrung Bön such as Zhitro, Yoga of the Peaceful and Wrathful Deities. This is given as an initiation and should be practised during the lifetime to enable one to recognize the manifestations of this Bardo when they appear and attain liberation at this stage. Alternatively this practice is done by living friends or other practitioners to purify the obscurations and defilements of the deceased's mind and enable them to be liberated or, at least, obtain a better rebirth.
For those who did not receive any teachings or initiations, these manifestations will appear as external, often frightening, emanations chasing one's spirit which cannot hide anywhere. One is blown like a helpless feather by the hurricanes of the karmic winds arising from one's previous actions. An experienced lama can help the troubled spirit even at this stage, leading them to liberation or a better rebirth by performing a Phowa practice or a Jyangbui Choga ritual in the course of which the deceased's consciousness is summoned into a support and instructions regarding the Bardo are read, or by reading the Bardo Thödrol text. The Bardo of Taking Rebirth is generally said to last forty-nine days, but this is an approximation. Indeed, some beings may skip this stage along with the two previous Bardos. This is true for realized practitioners who become a Buddha before or straight after dying, as well as for those who go straight to hell because they committed one or more of the Five Actions Without Interval:
Killing a spiritual adviser or lama;
Killing a student of a spiritual teacher;
Killing one's father;
Killing one's mother;
Killing one's own child.
Those who committed these grave negative actions are instantly reborn in one of the eighteen hells when they die. Furthermore, the minds of some religious practitioners who were killed or disturbed while dying and thus became trapped in one of the negative emotional states may turn into a very dangerous spirit immediately after passing for a brief moment through the Bardo of Primordial Dharmakaya.
~Excerpts from Bo & Bon by Dmitry Ermakov