RichThesaurus
marble-hearted
vs
remorseless
marble-hearted
adj
Emotionally cold, cruel, and unfeeling.
remorseless
adj
Unyielding or relentless.
Without remorse, mercy or pity.
How often have the words
marble-hearted
and
remorseless
occurred in a corpus of books?
(source:
Google Ngram Viewer
)