The King of Horror has written some of the most unhinged and terrifying villains in literary history. There's a lot of divide over whether Randall Flagg or Pennywise is the worst, but I think that one of the most evil and underrated villains of King's is the Library Policeman/Ardelia from the novella of the same name. Ardelia could have used all manner of methods to try and return to the living, but I personally think that forcing Sam to reflect on his traumatic childhood assault is much worse than violence. Sam can run and hide from a threat, but he can't escape his own mind.