妖孽用英语翻译为 "demon" 或 "monster". 这个词源自汉语，意思是指邪恶或者恶劣的人。例如：

He is a demon who will stop at nothing to achieve his goals. 他是个不择手段达到目的的恶人。

She is a monster who will hurt anyone who gets in her way. 她是个伤害任何阻挡她的人的恶人。

希望这能帮到你！