Silver Banshee is Siobhan McDougal. She is a supervillainess.She was the first-born child of Garrett McDougal, the patriarch of an old Gaelic clan that has occupied an island midway between Scotland and Ireland for a thousand generations. On that island is Castle Broen, where first-born McDougals enter to undergo a ritual to prove themselves worthy to lead the clan. When Siobhan was young she traveled the world, only returning to Castle Broen when she heard of her father's death. Her uncle Seamus determined that no woman would lead the clan, and intended her brother Bevan to become the new patriarch. She went ahead with the family ritual by herself, which involved calling on supernatural forces for power. She was interrupted by Bevan, and the distraction proved disastrous as she was dragged away into an infernal netherworld. An entity called the Crone granted her powers and the ability to return to Earth as the Silver Banshee.She appears on Supergirl(2015)