Villian(s)  Demonic possession

Actor(s):  Linda Blair, Richard Burton, Louise Fletcher, Max von Sydow

Brief Description  Exorcist II: The Heretic (1977) is an American supernatural horror film directed by John Boorman and written by William Goodhart. Serving as the direct sequel to the iconic 1973 film The Exorcist, it picks up four years later and follows a 16-year-old Regan MacNeil who is seemingly recovering from her past demonic possession while still struggling with repressed memories and bizarre nightmares.

Plot:
Father Philip Lamont (Richard Burton) is tasked by his cardinal to investigate the tragic death of Father Lancaster Merrin, who died during Regan's original exorcism. Lamont feels spiritually unfulfilled and fears that Evil is winning the global battle against Good. Regan (Linda Blair) is under the psychiatric care of Dr. Gene Tuskin (Louise Fletcher). Dr. Tuskin utilizes a state-of-the-art biofeedback device that hypnotizes and links the minds of two people together. When Father Lamont attaches himself to the device with Regan, they uncover that the ancient demon Pazuzu still actively lurks within her subconscious, desperate to break free and cause ultimate havoc. Through these hypnotic visions, Lamont discovers that Father Merrin had previously cast out the exact same demon from a young boy named Kokumo in Africa. Hoping to find answers on how to permanently defeat the entity, Lamont travels to Africa to track down the now-grown youth, learning horrific secrets about locust swarms and the "Locust Mind" along the way.