"Antagonist" is the standard literary term for a character who is opposed to the protagonist. A less formal (but also less specific) term for such a character is "opponent". Such a character may be evil, like say Darth Vader in Star Wars. Or such a character may simply be a competitor, such as say a player on an opposing team in a sports movie. Often such a character is portrayed in a negative fashion, because that can make for more drama.
When an antagonist is also portrayed as evil or negative, the term "villain" may be used in place of "opponent". This is less formal than "antagonist" but less colloquial than "bad guy". Indeed it can be used as a near synonym for antagonist.
However, where a viewpoint or central character is portrayed as evil or immoral or amoral, the term "Anti-hero" may be used. An anti-hero is generally the protagonist or central figure of the work, but is portrayed as evil or in some other way as non-heroic. For example the character Parker in the series of novels by Donald Westlake (writing under the name Richard Stark) is a classic anti-hero. Parker is a criminal, and a killer, when it seems to him in his interest to kill. He has little or no affection for anyone but himself, and does not understand why anyone would expect him to. He is surprised when other characters act out of some sort of friendship for him. But he is the central figure, and the primary viewpoint character, and most readers will identify with him.
See the Wikipedia article. See also dictionary.com, Cambridge dictionary Writing Explained, and Britannica All suggest that an anti-hero is "a protagonist of a drama or narrative who is notably lacking in heroic qualities" which is different from simply being an antagonist.
Responding to the added examples, the Joker in the various versions of Batman is an antagonist or opponent, and could also be called a villain or bad guy. (None of these are adjectives, I'm afraid, but descriptive nouns.) Cersei Lannister in the Game of Thrones novel series (I have not watched the video version) was certainly both an antagonist and a villain ("bad guy" sound wrong for the tome of this series to me). Littlefinger is clearly an antagonist, and arguably a villain. Joffery Baratheon is also clearly an antagonist, but I would be reluctant to call him a villain. If he had been the central character, he might have been an anti-hero. I do not know the other characters listed, and so cannot comment on them.