Short answers, pulled from the story.
The German Student Union, abbreviated DSt, was founded in 1919 as a democratic merger of the general student committees of all German universities, including those in Danzig, Austria, and the former German universities in Czechoslovakia. It operated until 1945, when it was banned as a Nazi organisation.
The National Socialist German Students' League dominated the DSt from 1931 onward. The two organisations were formally merged on the 5th of November 1936 under Gustav Adolf Scheel, who served as Reichsstudentenführer of both bodies.
The DSt played a large part in the Nazi book burnings of 1933. On the 6th of May 1933, its members made an organised attack on the Institute of Sex Research in Berlin's Tiergarten area, after which around 20,000 books and journals and 5,000 images were burned at the Opernplatz.
Members of the DSt attacked the Institute of Sex Research in Berlin's Tiergarten area on the 6th of May 1933. A few days later, the institute's library and archives were taken out and burned in the streets of the Opernplatz, destroying around 20,000 books and journals and 5,000 images.
Gustav Adolf Scheel was the last leader of the German Student Union, holding the position from February 1936 until 1945. Following the merger of the DSt and the NSDStB on the 5th of November 1936, he held the title of Reichsstudentenführer over both organisations.
The German Student Union was banned in 1945 as a Nazi organisation. From 1931 it had been dominated by the National Socialist German Students' League, and in 1936 the two bodies were formally merged under Gustav Adolf Scheel, making the DSt an official part of the Nazi state apparatus.