What is a preson who represents the opposite of a person?

A person who represents the opposite of another is often referred to as an "antithesis" or "foil." This individual embodies contrasting traits, beliefs, or values that highlight and amplify the characteristics of the original person. In literature and drama, foils are commonly used to enhance the complexity of characters and themes. By presenting opposing qualities, they create a more dynamic narrative and deepen the audience's understanding of the main character.