proscriber — English Dictionary

Noun

1. One who, or that which, proscribes, denounces, or prohibits.

   Examples

   In a period of quiet, he had acquired the name of a man of worth; in darker days, he left the renown of a pitiless proscriber.

   More examples (1)

   “In principle,” he declared, “proscription is not only a crime, but a fault; history is full of instances, showing how proscribers have in their turn been forced into the ranks of the proscribed."

   I made no connection to the fact that the other proscribers of books were Hitler and the Catholic Church.