In the second season of American Horror Story, "Asylum," we meet Sister Mary Eunice McKee, played by the talented Lily Rabe. At first glance, Sister Mary Eunice appears to be the picture of kindness and compassion, dedicated to caring for the patients of the infamous Briarcliff Manor. However, beneath her angelic appearance lies a terrifying darkness. Throughout the season, we witness Sister Mary Eunice's transformation from a devout nun to a being possessed by a demonic entity.