In late 19th/ early 20th century German occultism, the terms Vril-ya and Fraja played an important role. The similarities with the OLB name Frya (as well as some of OLB's themes) are remarkable.
Quotes from "Walpurgis Night - Volume One 1919-1933" by Thomas Sheridan, (2014):
pp 105-107 (parts made bold and added hyperlinks by me):
In 1871, a novel by a Rosicrucian named Edward Bulwer-Lytton entitled, [pp. 110-111:
...] the Coming Race, is perhaps the first work of science fiction designed to generate a sense of expectation within readers, in that the storyline itself would eventually come to pass. [...] Influential occult figures such as Helena Blavatski and Rudolf Steiner, along with other Theosophists, claimed that the book's narrative of a master race living inside a hollow earth who possess the power of an energy form which they called Vril was rooted in fact.
In the story, a young adventurer discovers a subterranean civilisation of angelic Aryan-looking beings called the Vril-ya. The Vril-ya, who were once human, went to live inside the earth before the Great Flood as described in the Bible. [...]
[...] the one aspect of Edward Bulwer-Lytton's novel which really captured the imagination of occultists of the time such as the Order of the Templars and Thule Society in Germany, was the energy force of the Vril-ya; the "all-permeating fluid" of Vril, which the Ariosophists took to mean Aryan blood. A force, if kept pure and free from being contaminated by other inferior blood races, could unleash incredible psychic and energetic forces according to the training of one's will. [...] The suggestion is made in the novel that the Vril-ya will eventually return to the surface of the earth if a pure racial Aryan blood group evolves on the surface of the planet, taking with them their awesome magical powers and sharing these powers with the surface Aryan master race. The idea so excited members of the Thule Society that they formed a group in Berlin called Wahrheitsgesellschaft, or The Society for Truth, which was charged with discovering the power of Vril and using it to create wonder weapons.
Within the pages of Ostara, there were articles that contained what Lanz von Leibenfels termed 'Fraja-Christus' or the new Aryan Jesus of the coming order. This obviously influenced the young Hitler enormously, especially the articles entitled Sexual-Physics as Odylic Energy.p.130:
A few weeks after the death of Guido von List, members of the Thule Society conducted a seance inside the Four Seasons Hotel [Munich], involving a Russian female peasant who - if reports are to be believed - manifested the spiritual forms of the murdered Prince von Thurn und Taxis and Countess von Westarp. To the terrified and amazed attendees, the ghosts of the murdered Thule Society aristocrats announced the imminent arrival of the German Messiah who had been longed for all these dark years. The dialect in which the spirits allegedly spoke was the 'Low German' (Plattdeutsch), derived from the ancient Old Saxon tongue. However, the apparitions also came with a dire warning that this Messiah would be a false prophet who would lead Germany into destruction.p.148:
It was almost as if Hitler had been brought out of his shell just by being in contact with the Thule Society, and by summer 1919, was being 'tested' to see if he had what the Thule Society needed from him: the potential to be the 'Fraja-Christus': the Aryan Jesus of the resurrected Germany.
One can easily find information about Vril on the web and the book can be read online, but it is hard to find soures about the 'Fraja' redeemer. I guess that not only the WW2 victors, but also the National-Socialists themselves have tried to keep this information hidden (most of Germany was and is still of the Christian religion).