A Drow spirit
This mercenary drow spirit is not out & out evil but remains aloof & generally unfriendly. He stays in Listach working as a scout & spy for Sarr Tamm as it is preferable to wandering the shadowfell or the fate he would have faced in hell at the hands of the Drow goddess: Lolth.
In life, Bidra’an was a youngest son of a minor noble family in Menzoberranzan. As can happen in the matriarchal Drow society, the lowly male was set to be sacrificed to Lolth. However, as he was led to the altar, Bidra’an cursed the name of Lolth & committed suicide, disgracing the Matron Mother of the Diss family & denying Lolth ownership of his soul.