Rkkr means shadow . Ragnarok is, therefore, the going into the shadow of the gods. Yet again, although the Rkkr can be seen as the darkness that consumes the gods of Asgard, they are more accurately seen as the shadow: causal emanations of the acausal darkness. Only by looking into the shadow, is it possible to glimpse the black enormity of the darkness that is the goddess.
The shadow is the soul. It is the visible evidence of what exists within. To the Egyptians, one of the seven souls of a human being was the khaibut (the shadow that is the image of the self, often seen in reflections). This was echoed in the classical world, where the soul was the umbra (shade), which travelled to the Land of Shades upon death. There, the shade was welcomed by the goddess Nephele (cloud), whose chthonic aspect meant she was associated with Hekate and Persephone, although she was also seen as a form of mother Hera. She was also the mother of the bright maiden Helle.
The Rkkr form of this Land of Shadows is Nifelheim, ruled by Hela under her name of Nifl. The word Nifl is practically another form of Rkkr, having the multi-layered meanings of clouds, obscurity, mist, fog, and darkness (appearing as the Old High German nebul, Old Saxon nebal, German nebel). It is no accident that Nifl has the same meaning as the Greek name Nephele, as both represent the dark, shadow of Hela and Hera respectively. This strain of goddesses can be found in Egypt in dark Nephthys, the wife of Set (whose Rkkr equivalent is Surt), and the goddess of the underworld and the sunset. In Semetic legend, also, the fallen angels, the Nephilim, were the children of the pre-mosaic goddess Nephesch, who was referred to as the Soul of the World, and was twinned with the light Shekinah. Children like the Nephilim also belong to Nifl-Hela, and are called the Niflungar, more familiar as the Nibelungs.
In Nifelheim, all beings manifest as shadows, because they appear through the eyes of Nifl-Hela, mistress of the veils. To her, all human and divine striving is fleeting and futile (something that Loki also teaches, but with humour), and so pass like shadows. The great mystery is that Nifelheim is a microkozm of Midgard and all the nine worlds, so when humans or gods think they are existing in the world, they are only passing like shadows. Nifl-Hela is the World Soul, while the giant Rkkr, who emerge from her womb, are the shadowy souls of all beings; all giant races: the Nephilim, the classical Titans, and the Hindu Rishi, are all soul forces which gain their sustenance from the blood of the goddess.
extracted from:http://shadowlight.gydja.com/shadow.html
I don't think I would agree on much of this. Your interests are well placed, but you seem to be lacking the proper correct sources. Abby Helasdottir coined the term of Rokkr. It is simply to express the more chaotic nature, the more savage and instinctual nature of the gods. It is not merely just a shadow. Take Fenrir for example. He is the wolf-son of Lopt. Not often do I work with him, but when I do, I feel he is propelled by his instincts. He has a more natural, predetorial tone to him. Ran is another one. She is the Norse Goddess of the sea. The sea is a primal force of nature. A dangerous and chaotic form of nature. And the Niflhiem bit passing off the locals as shadows is untrue. That sounds more like a UPG than fact. The whole womb story seems to be passed off as well. I've never read anything like that nor have I heard it discussed.
