the villain of the piece

someone or something that has caused a bad situation

Usage notes: This phrase was first used to describe an evil character in a play.

According to reports of the disaster, the villain of the piece is the mining company who failed to carry out proper safety checks.

Name	Pronounced	Usage
Agars	['eiga:z]
Konnor	KAHN-ər	English (Modern)
Ellery	EL-ə-ree	English
Diana	die-AN-ə (English), dee-AH-nah (Italian, German, Dutch)	English, Spanish, Italian, Portuguese, Romanian, Catalan, German, Dutch, Danish, Swedish, Norwegian,
Viljami	VEEL-yah-mee	Finnish
Heru	-	Egyptian Mythology