Banshees are one of the most powerful Husk variants, being Asari (usually Ardat-Yakshi) that have been transformed into mindless servants of the Reapers. Commander Shepard and his/her allies first encounter them on the planet housing the Ardat-Yakshi Monastery, where they have already transformed numerous Asari. More are encountered on most Reaper-held worlds thereafter. It can be safely assumed that after the fall of the Asari homeworld Thessia the Banshee's numbers increased. They were presumably wiped out when the Reapers were defeated at the end of the war.