castigator
A castigator is a person or entity that administers punishment or severe criticism. The term derives from the Latin word "castigare," meaning to chastise, correct, or punish. Historically, a castigator might have been an official tasked with enforcing discipline or meting out penalties. In a broader sense, the word can refer to anyone who subjects another to harsh disapproval or condemnation. This can manifest in various forms, from verbal reprimands to public shaming or more formal sanctions.
The act of castigation implies a judgment that the recipient has transgressed a rule, norm, or expectation.