Special Guest Stars Matt Ryan as John Constantine Neal McDonough as Damien Darhk Wentworth Miller as Leonard "Leo" Snart / Citizen Cold Guest Stars Jes Macallan as Agent Ava Sharpe John Noble voices Mallus Tracy Ifeachor as Kuasa Madeleine Arthur as Nora Darhk Marilyn Norry as Dr. Ellen Moore (2017) Annabel Marshall-Roth as Dr. Ellen Moore (1969) Co Starring Craig Fraser as Attendant Kelly Metzger as Doctor
