Short answers, pulled from the story.
Åke Ohlmarks was a Swedish author, translator, and scholar born in Kristianstad on the 3rd of June 1911 and died on the 6th of June 1984. He is best known for his controversial Swedish translation of J. R. R. Tolkien's The Lord of the Rings and for a 1939 academic study of shamanism. He published around eighty works of popular science and history as well as roughly as many translations across his career.
Tolkien objected because Ohlmarks invented his own expressions, shortened large portions of the text, and inserted his own interpretations into the narrative. Tolkien also disliked the title Ohlmarks chose, Sagan om ringen, meaning The Saga of the Ring. Tolkien's dissatisfaction was serious enough that he compiled his "Guide to the Names in The Lord of the Rings" specifically in response.
In 1982, Ohlmarks published a book titled Tolkien and Black Magic, which put forward a conspiracy theory connecting Tolkien and Tolkien fandom with Nazi occultism. The book appeared after years of sustained criticism of his translation from both Tolkien himself and Swedish Tolkien readers.
Ohlmarks's translation remained the only Swedish-language version of The Lord of the Rings until 2005, when Erik Andersson and Lotta Olsson published a completely new translation.
From 1941 to 1945, Ohlmarks held a position as docent and associate professor in the Swedish language at the University of Greifswald. He founded an institute for religious studies there alongside a member of the Deutsche Christen movement. He did not align his scholarship with National Socialist ideology and denied being a Nazi, but his conduct has been described as opportunistic, combining adaptation, collaboration, and ignorance. He left the city shortly before it was taken by the Red Army.
Ohlmarks published Studien zum Problem des Schamanismus in Lund in 1939, examining the problem of shamanism in Nordic and comparative religious history. It is considered his most notable scholarly contribution. A related paper the same year, Arktischer Schamanismus und altnordischer Seiðr, appeared in Archiv für Religionswissenschaft.