who is the song angel of death about
Nazi physician Josef Mengele's human experiments at the Auschwitz concentration camp during World War II.
Angel of Death (Slayer song)
the Nazi physician Josef Mengele's human experiments at the Auschwitz concentration camp during World War II. 
wiki:19484861
Angel of Death (Slayer song) [SEP] Introduction
"Angel of Death" is the opening track on American thrash metal band Slayer's 1986 album "Reign in Blood". The lyrics and music were written by guitarist Jeff Hanneman. They detail the Nazi physician Josef Mengele's human experiments at the Auschwitz concentration camp during World War II. Although the lyrics describe Mengele's abuses rather than endorsing them, "Angel of Death" led to accusations of Nazi sympathizing and racism against the band, which they vigorously denied but which followed them throughout their early career. Despite the controversy and the resulting delay in the release of "Reign in Blood", the song remains a live favorite, and has appeared on all of Slayer's live albums.