YMMV / The Twilight Zone (1959) S3E6: "The Mirror"

• Complete Monster: Ramos Clemente is a peasant turned revolutionary who overthrows the tyrannical General de Cruz. When warning signs arise in Clemente's sudden fits of rage and his unhinged demand that de Cruz be executed via being stripped, slathered in honey, and consumed by ants, Clemente becomes enamored with the former dictator's supposedly Magic Mirror. Believing his own childhood friends plot against him upon seeing their images in the glass, Clemente callously murders them and begins ordering the executions of thousands of prisoners around the clock, becoming a more loathed tyrant than de Cruz himself. When confronted, Clemente proclaims that he'll execute people all day until the populace gets used to it.
• Tearjerker: What Clemente's madness does to his childhood friends. They know that something is very wrong with him, and repeatedly ask him if everything's OK, only to be killed by him. It's likely they spent their last moments wondering just what they had done wrong and worrying about their friend. Cristo in particular dies feeling sad, not that he's dying, but because Clemente will now be all alone in the world.
• Unintentional Period Piece: While there are still regimes around the world, the episode specifically is based on Latin American dictators such as Fidel Castro, who are long dead by The New '20s. It's also based on the events of the Cuban Revolution, a fairly obscure event today but a highly relevant topic during the time of airing.