one who oppresses or exercises authority in a cruel manner

अत्याचारी

English Usage: The oppressor was finally brought to justice after years of suffering inflicted on the people.

Hindi Usage: अत्याचारी को आखिरकार न्याय के कटघरे में खड़ा किया गया, जो लोगों पर वर्षों तक दुख देने वाला था।