Antagonist

An antagonist (from Greek ἀνταγωνιστής - antagonistēs, "opponent, competitor, enemy, rival", from anti- "against" + agonizesthai "to contend for a prize,") is a character, group of characters, or institution that represents the opposition against which the protagonist or protagonists must contend. In other words, an antagonist is a person or a group of people who oppose the main character(s).

In the classic style of stories wherein the action consists of a hero fighting a villain/enemy, the two can be regarded as protagonist and antagonist, respectively. Of course, some narratives cast the villain the protagonist role, with the opposing hero as the antagonist.

The antagonist may also represent a major threat or obstacle to the main character by their very existence, without necessarily deliberately targeting him or her.

Examples in both film and theatre include Sauron, the main antagonist in The Lord of the Rings, who constantly battles the series' protagonists, and Tybalt, an antagonist in Romeo and Juliet, who slays Mercutio and whose later death results in the exiling of one of the play's protagonists, Romeo. A convention of the antagonist in a story is that their moral choices are less savoury than those of the protagonist. This is often used by an author to create conflict within a story. However, this is merely a convention and the reversal of this can be seen in the character Macduff from Macbeth, who is arguably morally correct in his desire to fight the tyrant Macbeth.

Primary Antagonists
Main Antagonists are the most important antagonists in a story. They are the character(s) who are responsible for a major event that the story revolves around and are the enemy who the main character must defeat. In video games, the main antagonists are frequently the final boss. The antagonistic character can return in sequels either reclaiming their position as the main villain, or appear as a lesser character.

Secondary Antagonists
Secondary Antagonists are villains who are of second most importance in a story. They can be seen as a minion to the main antagonist, or a separate character with their own personal agenda. A main example of a secondary antagonist is Starscream from the Transformers, who is the second-in-command to Megatron, the primary antagonist of the franchise. Starscream serves Megatron, but truly wishes to overthrow his master so that he may rule the Decepticons himself. Also, in some cases, the secondary antagonist returns in a sequel as the main antagonist, to avenge the former villain who dies in the previous work. Other times, the secondary antagonist will become the true main antagonist, revealing themselves to have been the cause of the events in the story, while the initial antagonist is either killed or reforms and assists the protagonist on fighting the new villain.