Damien: Omen 2
All the people who try to to stop Damien get killed brutally, including his own stepfather, who gets killed by his wife, telling him that she has always served "him".
Satan (as a raven) kills Aunt Marion (Sylvia Sidney) with a heart attack and Joan Hart (Elizabeth Shepherd) by blinding her so that she gets overrun by a truck. Manager Bill Atherton (Lew Ayres) drowns in ice, his successor Pasarian (Allan Arbus) gets killed by steam from a broken pipe, Dr. Kane (Meshach Taylor) gets cut in two in an elevator.
After Damien's drill sergent (Lance Henriksen, very young at that time!) tells him to read Revelation in the Bible, Damien finds the "666" on his head in a mirror and realizes who he is. His kills his cousin Mark (Lucas Donat) with a thought, because Mark had heard Dr. Charles Warren (Nicholas Pryor) telling his stepfather Richard Thorn (William Holden) that Damien is the Antichrist.
When Richard Thorn decides to look at the evidence (a picture showing Damien as the Antichrist), his friend Charles gets crushed by a train.
Richard decides to kill Damien with the holy daggers. His wife Ann (Lee Grant) tries to persuade him not to do it, but fails. She then kills Richard and tells that she has always served "him".