A villain or antagonist role — the character who opposes the protagonist or behaves badly in a story, play, or film.
彼は映画でいつも悪役を演じている。
He always plays the villain in movies.
子どもの頃はよく友達と悪役の真似をして遊んだ。
When I was a child I often pretended to be the villain with friends.
その漫画の悪役は最後に改心する設定だ。
The villain in that manga is set to reform in the end.