utter villain; atrocious fiend; devil
Strongly negative term for a person of extreme evil; often used in dramatic or literary contexts.
He went down in history as an utter villain.
The atrocious fiend in that story evokes strong disgust in readers.
Compound of 極 (extreme), 重 (heavy/severe), and 悪人 (villain). The exact historical derivation is uncertain, but the combination intensifies the notion of a deeply evil person.