Served in the German Waffen-SS division Wiking as a volunteer during World War 2. One of only about 180 confirmed Swedish volunteers, Nystrand undertook basic military training in Sennheim (Alsace) and Klagenfurt (Austria) in 1941 before being sent to Yugoslavia to fight the partisans. Later he was sent to the Eastern front where he saw combat in the Ukraine. He left the Waffen-SS in 1942. After the war he became a teacher in Swedish and history and settled down in Varberg, Sweden. He wrote a series of quite successful novels about Roland Rethelius, his alter ego. In 1965 he debuted as a screenwriter with "Här kommer bärsärkarna". The movie received terrible reviews from critics.
