1.
mastermind; wire-puller; power behind the scenes
A person who secretly controls or influences events from behind the scenes, especially in politics or crime. Originally referred to the black curtain used in kabuki theater to hide stagehands.
Etymology
From 黒 (black) + 幕 (curtain). In kabuki theater, a black curtain hides stagehands who move props and assist actors. By extension, the word came to mean someone who operates unseen, pulling strings from behind the scenes.
Usage
Used in news, politics, and crime stories. Also common in manga and anime to describe the secret villain controlling events. Almost always carries a negative connotation.