In The Conjuring 2, Ed and Lorraine Warren encounter a demonic nun figure named Valak. At the end of the film, Lorraine learns the demon's name and manages to banish it to hell. while audiences may have thought the film would be the last they'd see of Valak, she returns in The Nun.
Vera Farmiga's real-life sister, Taissa Farmiga, also stars in The Conjuring prequel, The Nun, as Sister Irene, sparking speculation that the two characters are connected, whether they are the same person, sisters, or related in some way.