Therion lyrics are so colorful and symbolic that you can´t try to understand it by a political mysticysm like NS ideology. The symbol of the Black Sun is very complex if you want to describe with objective words, but you can give mundane names with some sciences to understand it. For example, you can view it as the Unconciouss power inside the nature of human being, the inner core of the big bang explosion, the manifestation of the no-being of other realities, etc. If you want to understand a symbol, you should take attention in what it cause inside you and in the colective uncounciousness.
The association of the spear of destiny and the Black Sun is the heroe myth of the Descensus ad Inferos (descend to the underworld). For example Odhinn, whom spear caused him to enter in the realms of the other reality, due to it´s Necessity to gain wisdom and knowledge from the dark depths, and if you see the runes there is one who´s name is Naud (need and destiny), and this is the rune of Odhinn. You can associate the black sun also with the myth of Persefone, Quetzalcoatl, Amateratsu, etc.
To understand clear a therion lyric one must forget the mundane concepts of wisdom and to open your mind for all kind of possibilities and symbolism.
Black Sun - The energy from the dark realms of non existence manifested in the existence
Salud!
NTSMS has gone Frankfurt - again! 