Antagonist

An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.

[1] The English word antagonist comes from the Greek ἀνταγωνιστής – antagonistēs, "opponent, competitor, villain, enemy, rival," which is derived from anti- ("against") and agonizesthai ("to contend for a prize").

In some narratives, like Light Yagami and L in Death Note, the protagonist is a villain and the antagonist is an opposing hero.

Examples from television include J.R. Ewing (Larry Hagman) from Dallas and Alexis Colby (Joan Collins) from Dynasty.

In some cases, an antagonist may be a force, such as a tidal wave that destroys a city; a storm that causes havoc; or even a certain area's conditions that are the root cause of a problem.