avenger
An avenger is a person who seeks vengeance for a perceived wrong. The term can refer to someone who acts to retaliate or punish on behalf of themselves or others, sometimes within formal justice and sometimes outside it. The concept encompasses both vigilante figures and those who pursue justice through established legal means, depending on the circumstances and cultural context.
Etymology and usage: The word derives from Old French avengier, from Latin vindicare, meaning to defend, claim,
In culture and media: The avenger is a recurring archetype in literature, film, and television—a lone figure